Open Source Solutions.....

firefox and java plugin on linux

2010-06-15T06:06:00.001-07:00

1. Download jre-6u20-linux-x64.bin

2. ./jre-6u20-linux-x64.bin

3. ln -s /tmp/jre1.6.0_21/lib/amd64/libjavaplugin_jni.so /usr/lib/mozilla/plugins/libjavaplugin.so

4. ls -al /usr/lib/mozilla/plugins/libjavaplugin.so

update rhel4 packages

2010-06-14T23:14:00.000-07:00

You can use "update -u" to update the packages on RHEL4.

If it does not give you any indication of package updation try to clear cache (rm -rf /var/spool/up2date/*) and fire above command again.

Even if above method doesnt work. Login to your respective rhn satellite.
1. Select Critical, Non-critical packages.
2. Select All.
3. at the bottom, select update packages
4. then confirm.
5. ssh to the respective system, and run "rhn_update -vvv". It should show updating package details.

Good article on iscsi

2010-04-26T03:23:00.001-07:00

http://www.idevelopment.info/data/Unix/Linux/LINUX_ConnectingToAniSCSITargetWithOpen-iSCSIInitiatorUsingLinux.shtml#About%20the%20Author

How to select specific storage ?

2010-04-15T04:23:00.000-07:00

What is largest amount of data do you manage?

How much data is significant for you?

have you planned about deletion of data?

how ofter will you delete data? schedule?

Who is gone access your data? ex. applications, servers ?

are you planning to host your applications as well?

how must data application gone consume?

how much your application data may grow?

How busy will be your storage?

applications future plans?

How much data may grow in future?

If data not available, how does unavailability cost your org?

are you planning to archive data?

Why do you want to archive data?

how ofter are you planning to archive data?

for how long will you keep archive data?

existing data managements issues?

data center to manage data storage equipment?

Enough space in datacenter?

kickstart fully automatic installtion for rhel

2010-04-13T23:29:00.000-07:00

Note: Please remember options may vary depend on OS, network settings, os update version etc.

This fully automatic installation cfg is for RedHat 5 OS.

install
text
nfs --server=192.168.1.9 --opts=tcp --dir=/pub/rhel/released/RHEL-5-Client/U5/i386/os
keyboard us
lang en_US
key --skip
reboot --eject
selinux --disabled
firewall --disabled
rootpw redhat

timezone --utc Asia/Kolkata
network --onboot yes --bootproto dhcp --gateway 192.168.1.1 --nameserver 192.168.1.10

#Setup default services
services --disabled=cups,messagebus,ip6tables,isdn,pcmcia,hidd,bluetooth --enabled=ntpd,nscd

# Disk Setup

bootloader --location=mbr --append="rhgb console=tty0 console=ttyS0,9600"
clearpart --all

# auto disk partition
part /boot --fstype ext3 --size=100
part swap --fstype swap --size=2048
part pv.1 --size=0 --grow
volgroup AutoVolGroup pv.1
logvol / --vgname=AutoVolGroup --name=root --size=1 --grow

%packages
@core
@system-tools

%post
cat <> /etc/motd
Lab automatic kickstart installation.
Installed `date`
EOF
cat /etc/motd >> /root/ks.cfg

disable selinux on the fly

2010-04-07T22:16:00.000-07:00

To disable selinux on the fly you should run following command in terminal,
setenforce 0

to disabled it permanently, open /etc/selinux/config and change value to SELINUX=disabled

How to upgrade firmware on Dell DRAC?

2010-02-19T01:07:00.000-08:00

DRAC stands for Dell Remote Access Controller. The DRAC on current models is a separate chipset and board that is connected to the server main board with its own network interface as well as a direct configuration accessible during system initialization.

DRAC has a default TCP/IP address and can be change during system initialization

I found dmidecode currently does not return any information about DRAC card on the system. If you have system tag with you can check online if systems include DRAC card.
* Put you system tag here,
http://support.euro.dell.com/support/topics/topic.aspx/emea/shared/support/my_systems_info/en/details?c=uk&l=en&s=gen
* Click on "Original System configuration"
* Search for "DRAC"

Here is firmware upgrade process.

* Download the firmware for your system, In my case it was Power Edge 2950 system. I found firware versions here.

* Download windows zipped exe file and extract it.There should be only one file named "firmimg.d5".

* Copy the same to your tftp server at /tftpboot/pxelinux.cfg/ location. (Can share it and mount on tftpserver or use WinSCP to copy files to remote unix system)

* Login to drac server using the IP assigned to DRAC.
Before upgradation firmware version

[root@npatil ~]# ssh drac-ip
root@drac-ip's password:

Dell Remote Access Controller 5 (DRAC 5)
Firmware Version 1.0 (Build 06.05.12)

$ racadm fwupdate -g -u -a tftpserver-ip-address -d firmimg.d5
Firmware update completed successfully. The RAC is in the process of
resetting. Please wait up to a minute for this to complete.

Please do not make any changes in DRAC configuration while doing firmware upgradation.

It may disturb upgrade process.

After upgradation Firmware Version

[root@npatil ~]# ssh drac-ip
root@drac-ip's password:

Dell Remote Access Controller 5 (DRAC 5)
Firmware Version 1.20 (Build 07.03.02)

SAN terminologies

2010-02-07T22:22:00.001-08:00

Here I am trying to put every definition related to SAN on single page. Its a collective information from different sites.

AoE: ATA over Ethernet: its a network protocol designed to access SATA storage devices over the Ethernet networks. AoE does not rely on network layers above Ethernet, such as IP and TCP.
The advantage of AoE is that you don't have the overhead of translating ATA to SCSI and then back to ATA (if you are using ATA drives). So there is a performance pickup.

NBD: The Linux Network Block Device (NBD) is a device driver extension to the Linux kernel. With the NBD device driver you can create a TCP/IP network connection between your local Linux system and a server program on a remote (not necessarily Linux) computer. But NBD has some limitations in terms of read/write operation and using NBD as a root file system.
Server processing load for iSCSI is much higher than AoE for equivalent throughput. AoE can spare processing cycles. iSCSI requires TCP/IP and its requisite complexity.

ENBD- Enhanced Network Block Device
GNBD- Global Network Block Device

WWPN: World Wide Port Name. A globally unique identifier for a port which allows certain applications to access the port. The FC switches discover the WWPN of a device or host and assign a port address to the device.

Multipathing: When transferring data between the host server and storage, the SAN uses a multipathing technique. Multipathing allows you to have more than one physical path from the Server host to a LUN on a storage array.
If a default path or any component along the path—HBA, cable, switch port, or storage processor—fails, the server selects another of the available paths. The process of detecting a failed path and switching to another is called path failover.

An active/active disk array, which allows access to the LUNs simultaneously through all the storage processors that are available without significant performance degradation. All the paths are active at all times (unless a path fails).

An active/passive disk array, in which one SP is actively servicing a given LUN. The other SP acts as backup for the LUN and may be actively servicing other LUN I/O. I/O can be sent only to an active processor. If the primary storage processor fails, one of the secondary storage processors becomes active, either automatically or through administrator intervention.

Invalid command 'php_flag', perhaps misspelled or defined by a module not included in the server configuration

2009-10-26T05:58:00.002-07:00

Install php package and it will resolve the issue.

yum install php

how to configure APC pdu using minicom.

2009-09-16T05:30:00.000-07:00

Prerequisite:

PDU installation with proper network and console connection.

Configuration:
1. Run minicom -s -c on
-s - Setup. It has different option to setup your console. It edits /etc/minirc.dfl which is default to store configuration.
-c It usage color's on console.

Note: you can even run only "minicom -s"

Your screen should be like this,

┌─────[configuration]───-──┐
│ Filenames and paths │
│ File transfer protocols │
│ Serial port setup │
│ Modem and dialing │
│ Screen and keyboard │
│ Save setup as dfl │
│ Save setup as.. │
│ Exit │
│ Exit from Minicom │
└──────────────────-─┘

2. Select serial port setup option to select connect to correct serial device. I have terminated serial console cable from PDU to my Linux box so my device was /dev/ttyS0

It may differ depend on OS.

┌────────────────────────────────────┐
│ A - Serial Device : /dev/ttyS0 │
│ B - Lockfile Location : /var/lock │
│ C - Callin Program : │
│ D - Callout Program : │
│ E - Bps/Par/Bits : 9600 8N1 │
│ F - Hardware Flow Control : No │
│ G - Software Flow Control : No │
│ │
│ Change which setting? │
└────────────────────────────────────┘

3. I had to set Hardware Flow Control to No as it was Yes by default.

4. Choose Save setup as dfl to save the configuration. By default it save configuration in /etc/minirc.dfl. Here is my minirc.dfl.

# Machine-generated file - use "minicom -s" to change parameters.
pr port /dev/ttyS0
pu baudrate 9600
pu bits 8
pu parity N
pu stopbits 1
pu rtscts No

5. Once you save and exit from the setup. It intitialize the serial console and gives you access to PDU. The next screen would be something like this,

Welcome to minicom 2.1

OPTIONS: History Buffer, F-key Macros, Search History Buffer, I18n
Compiled on Jul 26 2006, 06:38:09.

Press CTRL-A Z for help on special keys

User Name : apc
Password : ***

6. Default username and password for apc PDU's are apc/apc.

American Power Conversion Network Management Card AOS v3.7.0
(c) Copyright 2008 All Rights Reserved Rack PDU APP v3.7.0
----------------------------------------------------------------------------------------------------------
Name : Engineering Rack PDU Date : 29.03.2000
Contact : Nilesh Patil Time : 19:23:22
Location : Server Room 1 User : Administrator
Up Time : 0 Days 5 Hours 0 Minutes Stat : P+ N+ A+

Switched Rack PDU: Communication Established

------- Control Console -------------------------------------------------------

1- Device Manager
2- Network
3- System
4- Logout

- Main Menu, - Refresh, - Event Log
>

7. Select 2-Network option to configure network. You can define network settings like ip, netmask, gateway etc.

------- Network ---------------------------------------------------------------

1- TCP/IP
2- DNS
3- Ping Utility
4- FTP Server
5- Telnet/SSH
6- Web/SSL/TLS
7- Email
8- SNMP
9- Syslog
10- ISX Protocol

- Back, - Refresh, - Event Log

8. Likewise you can configure your PDU as per your need.

How to setup rsync

2009-08-26T04:21:00.000-07:00

If you want to run rsync as a daemon make sure following thing.
- rsync is not hashed in /etc/services

- I have created following script to start rsync daemon which uses /etc/rsyncd.conf file

######### Creating start/stop script ..... /etc/init.d/rc.d/rsyncd

#!/bin/sh
# Rsyncd This shell script takes care of starting and stopping the rsync daemon
# description: Rsync is an awesome replication tool.

# Source function library.
. /etc/rc.d/init.d/functions

[ -f /usr/bin/rsync ] || exit 0

case "$1" in
start)
action "Starting rsyncd: " /usr/bin/rsync --daemon
;;
stop)
action "Stopping rsyncd: " killall rsync
;;
*)
echo "Usage: rsyncd {start|stop}"
exit 1
esac
exit 0

##########

######### Create /etc/rsyncd.conf file

### Rsync Configurations ###
uid = nobody
gid = nobody
use chroot = no
max connections = 10
syslog facility = local5
pid file = /var/run/rsyncd.pid
motd file = /etc/rsyncd.motd
lock file = /var/run/rsync.lock

[daily_backup]
path = /backup/
auth users = backup
comment = Main backup directory.
#### secrets file = /etc/rsyncd.secrets

IMP NOTE:
We should take care of trailing "/" while specifying the source directory for data copying.
for example,

rsync -avz -e ssh remoteuser@remotehost:/remoterdir/data/for/copy/ /local/data/dir

Above example means that /local/data/dir must be available to to receive data from /remoterdir/data/for/copy/, otherwise rsync will simply download all the files into the path given as destination.

rsync -avz -e ssh remoteuser@remotehost:/remoterdir/data/for/copy /local/data/dir
in this case "copy" directory will be created first under /local/data/dir directory and data will be populated from remote host.

I have created script to copy data remotely.

#!/bin/bash
# Script to copy data on remote machine.

RSYNC=/usr/bin/rsync
RSSH=/usr/bin/ssh
RUSER=backup
RHOST=backup.remote.host.com
RDATABASE=/backup/Database
RDIR=/backup/Directory/

$RSYNC -avz -e $RSSH /backup/daily/ $RUSER@$RHOST:$RDATABASE/MySQL/
$RSYNC -avz -e $RSHH /var/www/html/ $RUSER@$RHOST:$RDIR

Please generate password less keys to copy data remotely without interruption. Use "ssh-keygen"

Postgresql backup and restore.

2009-08-24T05:05:00.001-07:00

First method using pg_dump and second one is file system level backup.

Dump level Backup:
pg_dump dbname > outfile

Options available with pg_dump,
-h hostname. Default is localhost or whatever is set in PGHOST variable.
-p which port. PGPORT env.
-U username. default is logged in user name. PGUSER env.
outfile - name of the target file

Note:
pg_dump does not block other operations on the database while it is working. (Exceptions are those operations that need to operate with an exclusive lock, such as VACUUM FULL.)

Restore:
psql dbname < infile
infile - infile is what you used as outfile for the pg_dump command.

It is suggested to run analyze on each db to obtain the useful statistics. Run,
vacuumdb -a -z to VACUUM ANALYZE all databases;

pg_dump and psql can also use to dump a database directly from one server to another;
for example:
pg_dump -h host1 dbname | psql -h host2 dbname

2. File system level backup
tar -cf backup.tar /usr/local/pgsql/data
- Servers must be shutdown before taking backup.
- To restore database, we have to restore full database, can not do partial restore of tables or etc.

Open GUI application via ssh

2009-08-12T01:05:00.000-07:00

ssh -p 2222 -l nilesh -X -v {remote.host.ip.or.hostname}

-p 2222 In case your server runs a non-standard TCP port.
(If yours runs on the default port (TCP port 22), there is no need to add this option.)

-l nilesh is only required if you do not have matching usernames on remote host.

-X allows X forwarding. Use -x can be used to disable X11 forwarding

-v is verbose. This lets you watch what is going on.

Run your application once it is done.
I was about to run virt-manager GUI application, which ran successfully :)

Virtualization: Xen Installation

2009-08-12T00:45:00.000-07:00

How Xen works?
Xen hypervisor is run on top of the hardware which is the virtual machine monitor. Guest operating systems are run on top of this hypervisor, thus all guest operating systems are secondary to the hardware and contacts the hardware through the hypervisor. The first thing for grub would be to load the hypervisor. Look at the /boot/grub/grub.conf which loads the xen.gz-2.6.18-128.4.1.el5 which is the hypervisor.

Hypervisor loads the Dom-0 kernel and initrd image and starts the main system. Dom-0 itself is a guest operating system with additional privileges to manage other guest operating systems and is started with system start up.

Following rpms should be installed for Xen virtualization,
- kernel-xen ---> Dom-0 and Dom-U kernels.
- xen ----------> Xen hypervisor and other management tools.
- libvirt ------> Libraries required to manage domains which is used as a backend for virtmanager. http://libvirt.org
- virt-manager ----> GUI interface to manage guests

Once installation of above RPM's are done, System should be rebooted using the new XEN kernel.

Hidden ports on Linux.

2009-08-11T22:09:00.000-07:00

A nice blog post about the hidden ports on linux.
http://www.ossec.net/dcid/?p=87

FATAL_ERROR No password for admin user - please re-run ntop in non-daemon mode fir st

2009-07-30T23:52:00.000-07:00

When you install ntop, daemon does not start automatically. It returns above error when you try to start it.

You need to set password to start ntop in daemon mode.
"ntop -A" or ntop --set-passwd

It asks for password, set it.
Then start the service.
/etc/init.d/ntop start

You are now ready to view your network statitics :).

checking for intltool >= 0.35.0... ./configure: line 16914: intltool-update: command not found

2009-07-30T04:22:00.000-07:00

Error:
checking for intltool >= 0.35.0... ./configure: line 16914: intltool-update: command not found
configure: error: Your intltool is too old. You need intltool 0.35.0 or later.

Solution:
1. Install package, intltool-0.35.0-2.i386
2. It will fail for following dependency if XML Parser not installed.
error: Failed dependencies:
perl-XML-Parser is needed by intltool-0.35.0-2.i386
3. Also Download and install perl-XML-Parser package

Error! You need to have libevent 1.4.X or better.

2009-07-30T03:52:00.000-07:00

You need to install libevent-devel package. Please find the respective package for your OS and install it. Also check whether you have already install libevent.

How to monitor bandwidht using MRTG and Nagios

2009-07-29T04:25:00.000-07:00

Assuming that you have enough knowledge of Unix system and Nagios monitoring. If you dont know how to configure nagios please follow this link

Prerequisite:
- Make sure Nagios is running properly. Check http://localhost/nagios
- Also make sure that you have installed nagios_plugins.
- Iptables and Selinux must be disabled.

Install check_snmp plugin:
- Make sure you have all following packages install for successful installation of snmp plugin.
net-snmp, net-snmp-devel, net-snmp-libs, net-snmp-utils, beecrypt-devel,
elfutils-devel, elfutils-devel-static, lm_sensors

- To install check_snmp I download the plugin from this location. check_snmp

1. Unzip the downloaded file
bunzip check_snmp-1.1.tar.bz2

2. Untar it.
tar xvf check_snmp-1.1.tar

3. Configure and install it.
./configure
make
make install

4. Once it is install successfully you can find check_snmp at /usr/local/bin location.

5. Create a soft link for check_snmp.
ln -s /usr/local/bin/check_snmp /usr/local/nagios/libexec/check_snmp

Install MRTG:
To monitor bandwidth usages of router/switch you must have mrtg installed on system. Before installation please make sure you have install gd, libpng, zlib packages.

1. Download MRTG.

2. Once all libraries installed required for MRTG you are all set to compile and configure MRTG.
gunzip -c mrtg-2.16.2.tar.gz | tar xvf -
cd mrtg-2.16.2

3. ./configure --prefix=/usr/local/mrtg-2
make
make install

4. Create /var/www/html/mrtg file to store mrtg html files.
mkdir /var/www/html/mrtg

5. Now you need not to create mrtg configuration file. Use cfgmaker.
cfgmaker --global 'WorkDir: /var/www/html/mrtg' --global 'Options[_]: bits,growright' --output /etc/httpd/conf/mrtg.cfg public@172.17.42.22
( I choose default apache web location for installation of mrtg html files and apache conf directory to store mrtg.cfg.)

6. Go to respective location and make sure that above command has created respective files.
cd /var/www/html/mrtg;
ls -al /etc/httpd/conf/mrtg.cfg

7. Run this command to update mrtg log file.
env LANG=C /usr/local/mrtg-2/bin/mrtg /home/mrtg/cfg/mrtg.cfg

8. create a script to update the mrtg log file which will fetch data regularly and display in graph as well as on nagios.
vi /usr/local/mrtg-2/bin/monitor_mrtg.sh

9. Put following lines in it and save.
#!/bin/sh
env LANG=C /usr/local/mrtg-2/bin/mrtg /home/mrtg/cfg/mrtg.cfg
(When you run it first time it returns you few errors/warnings. Ignore it.)

chmod 755 mrtgbw.sh ; Make script executable.

10. Set cron to run above script every 5 minute.
crontab -e

11. Modify and save,
*/5 * * * * /usr/local/mrtg-2/bin/monitor_mrtg.sh

12. Restart cron service.
/etc/init.d/crond restart

13. Confirm that it is been configured.
http://localhost/mrtg/{name of html file}

Actually when you run mrtg command it searches for respective router community collects all data from router. Accordingly it creates log file. Like in my case it has found port 2 running on router and hence created file 172.17.42.22_2.log, 172.17.42.22_2.html. So I can access my graph through this link,
http://localhost/mrtg/172.17.42.22_2.html

Procedure to monitor Bandwidth Usages in Nagios:
1. Default installation directory of nagios is /usr/local/nagios/.

2. Open switch.cfg file
vi /usr/local/nagios/etc/objects/switch.cfg

3. Make changes according to your router specifications. Like,
define host{
use generic-switch
host_name Router_1
alias Router 1
address 172.17.42.22
hostgroups switches
}
4. You can also set PING, Uptime, Ports Link Status etc.
define service{
use generic-service ; Inherit values from a template
host_name Router_1 ; The name of the host the service is associated with
service_description PING ; The service description
check_command check_ping!200.0,20%!600.0,60% ; The command used to monitor the service
normal_check_interval 5 ; Check the service every 5 minutes under normal conditions
retry_check_interval 1 ; Re-check the service every minute until its final/hard state is determined
}

define service{
use generic-service ; Inherit values from a template
host_name Router_1
service_description Uptime
check_command check_snmp!-C public -o sysUpTime.0 -H 172.17.42.22
}

define service{
use generic-service ; Inherit values from a template
host_name Router_1
service_description Port 2 Link Status
check_command check_snmp!-C public -o ifOperStatus.2 -r 1 -H 172.17.42.22
}

define service{
use generic-service ; Inherit values from a template
host_name Router_1
service_description Port 2 Bandwidth Usage
check_command check_local_mrtgtraf!/var/www/html/mrtg/172.17.42.22_2.log!AVG!1000000,1000000!5000000,5000000
!10
}

5. Verify the configuration of nagios
/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

6. Restart nagios service.
/etc/init.d/nagios restart

Solaris: Disk Management

2009-07-21T05:15:00.000-07:00

- A disk under the Solaris OE can be divided into eight slices that are labeled Slice 0 through Slice 7.
- In reality Slice 2 represents the entire disk because "/" is the first(0) slice and swap is second(1).

Dist Slice Naming Convention, Controller number, Target number, Disk number, Slice number.
- Controller number, which control communications between system and disk unit.
- Target number is a unique hardware address of disk, tape, CDROM etc.
- Disk number is a logical unit number.
- Slice number is partition number on disk.

Solaris: Key points in File System

2009-07-21T04:30:00.000-07:00

Inode
In general inode contains two parts. First, inodes contains information about file, including owners, permissions, size etc. Second inode contains pointers to data blocks associated with files.

Different file types
Regular files
Directories
Device files contains block device and character device.
Symbolic links
Socket files

- Data block associated with directory contains lists of all files and associated inodes.
- Symbolic links can point to regular files, directories, other symbolic links and device files.
- A data block of symbolic link contains the path of original file.
- A long listing of a device file shows two numbers, separated by a comma where major number denotes specific device driver required to access the device and minor device denotes the specific unit of the device driver control.

Red Hat : Global File System

2009-07-15T22:01:00.000-07:00

- native file system.
- Interfaces directly with Linux kernel file system interface (VFS Player).
- Can be implemented on Standalone System.
- Can be a part of cluster configuration.
- GFS can be created on LVM logical volume.
- GFS is based on 64 bit architecture, can accommodate 8 EB file system.
- Red Hat GFS nodes can be configured and managed with Red Hat Cluster Suite configuration and management tools.
- LVM logical volumes in a Red Hat Cluster Suite are managed by CLVM, which is cluster wide implementation of LVM (clvmd daemon).
- daemon allow all nodes in cluster to share the volume.

OTRS: How to set the Generic Agent?

2009-07-07T03:21:00.001-07:00

Taken from, lists.otrs.org.

So you need to create as many jobs as you have agents.
The idea behind GenericAgent is very simple: search for tickets using the
values in sections shaded grey and set new values in tickets in sections
shaded black. You should have all your ticket types, queues, agents,
customers defined before you start making a GenericAgent job.

For example, we are building a job to assign Hardware problems to Mark
Twain.

In Admin, go to Generic Agent. Type in the job name Hardware_to_Twain and
click Add. A new job form appears. Study it a little. There are sections
with title shaded gray. The values you put into these sections' fields are
used to select the tickets for processing by the job. You select Agent/Owner
= root at localhost. You select ticket state = new. You select Ticket lock =
unlock, you select ticket type = Hardware problem. How do you plan to deal
with email tickets btw? They will not get tycket type set correctly.

Now we move to sections with titles shaded black. That's where we program
new values for ticket fields:
You select new Agent = Mark Twain. You select the new Queue = Hardware, New
ticket lock = lock.
You may add a note to leave trace of what has been done for your customer.
(It's reflected in the history for the agents anyway).
Check Send no notifications flag .

Go back to the beginning and think of the schedule for the job. How often it
should run?

AS soon as you save the job - you're done. If there are problems with the
job - look in the System Log.

OTRS: How survey module works?

2009-07-07T01:35:00.000-07:00

There are no steps given anywhere about how survey module works.
Here are the steps given,
1. Download and install Survey module
2. Login as OTRS Admin i.e. root@localhost by default.
3. Navigate to SysConfig setting under "Misc" section.
4. Search for Survey, then go to Core -> Survey::SendPeriod.
5. Change this value to 0, to send mail always whenever agent close the ticket.
6. Also created survey should have status as "Master". This is the setting when you create the survey.

This is where you can find more details, this post is translation from German.
http://translate.google.com/translate?hl=en&sl=de&u=http://wiki.otrs-forum.de/index.php%3Ftitle%3DSurvey&ei=3VWxSdOZCozMmQeRxJjfBQ&sa=X&oi=translate&resnum=8&ct=result&prev=/search%3Fq%3DSurvey::SendPeriod%26hl%3Den%26client%3Dsafari%26rls%3Den-us%26sa%3DG

Ganglia Installation errors and solutions.

2009-07-05T23:45:00.000-07:00

Error:
Checking for apr
checking for apr-1-config... no
configure: error: apr-1-config binary not found in path
make: *** No targets specified and no makefile found. Stop.

Resolution:
Install respective version of apr-devel. for me it was apr-devel-1.2.7-11.i386.rpm

Error:
Checking for confuse
checking for cfg_parse in -lconfuse... no
Trying harder including gettext
checking for cfg_parse in -lconfuse... no
Trying harder including iconv
checking for cfg_parse in -lconfuse... no
libconfuse not found

Resolution:
Install "libconfuse" and "libconfuse-devel" packages.

Error:
mod_python.c error: Python.h: No such file or directory
Resolution:
Install "python-devel" package if not installed.

- nilesh

Nagios: How to suppress notifications when host goes down.

2009-07-01T00:26:00.000-07:00

There are two ways to avoid extra notifications of services when host goes down.

1. Configure ping (use check-host-alive) as the host check, when the host is unreachable, the notifications for the services will not be sent.

2. Can have service dependency configuration file like this,
define servicedependency {
hostgroup_name all_servers
service_description ping check
dependent_hostgroup_name all_servers
dependent_service_description *
execution_failure_criteria w,c
notification_failure_criteria w,u,c
}

Nagios: How to monitor a website

2009-06-30T22:58:00.002-07:00

check_http supports arguments like hostname, hostaddress, URI etc.
you can have,
check_http -H $ARG1 -I $ARG2 -u $ARG3
where,
$ARG1 - hostname
$ARG2 - hostaddress
$ARG3 - URI - www.yourwebsite.com

Also check "check_http --help" for more details.

Nagios: Adding Cisco enterprise MIBs

2009-06-30T22:58:00.001-07:00

(Taken from nagios user list)

- Default directory for snmp mibs are /usr/share/snmp/mibs/ if you have libsnmp-base package installed.

- to verify that the mibs are working, you can use a mib browser such as mbrowse (apt-get install mbrowse).

- not all OIDs in a MIB are supported for all IOS versions. Cisco usually has a link for each IOS version and what MIBs are supported.

- once the mib is verified and working, use the check_snmp check_command
in your .cfg files of the routers and switches you want to monitor.

Nagios: Default parameter with check_total_procs

2009-06-30T22:57:00.001-07:00

We define service like this,

define service{
service_description Total_Processes
check_command check_nrpe!check_total_procs
…
}

By default this check is an execution of check_procs with only the warning and critical thresholds, so it counts all processes running on your machine.

The thresholds are configured in the nrpe.cfg on the remote machine.

- Nilesh

Install and Configure Nagios Plugins & NRPE on Solaris 10

2009-06-30T22:52:00.000-07:00

I came across lots of issues to do this installation so here is a step by step installation of Nagios Plugins and NRPE on Solaris 10.

Add “nagios” user as “/usr/local/nagios” as home directory.

# useradd -c “Nagios User” -d /usr/local/nagios -m nagios

Change ownership of directory to nagios

# chown nagios:nagios /usr/local/nagios/

download nagios-plugins and nrpe from net. I have download them from sourceforge.

# mkdir /nagios; cd /nagios

wget http://sourceforge.net/project/downloading.php?group_id=29880&filename=nagios-plugins-1.4.13.tar.gz

wget http://sourceforge.net/project/downloading.php?group_id=26589&filename=nrpe-2.12.tar.gz

Now extract them

# gunzip nagios-plugins-1.4.13.tar.gz; gunzip nrpe-2.12.tar.gz

# tar xvf nagios-plugins-1.4.13.tar.gz; tar xvf nrpe-2.12.tar.gz

Before compiling I had to set PATH to find gcc binary,

# export PATH=$PATH:/usr/sfw/sbin:/usr/sfw/bin:/usr/ccs/bin

# cd nagios-plugins-1.4.13;

# ./configure –without-mysql (I did want to install with mysql support)
# make; make install
# chown -R nagios:nagios /usr/local/nagios/libexec

Install NRPE with SSL library support otherwise you will get error while compilation like this,

“checking for SSL headers… configure: error: Cannot find ssl headers”

If you run “dmesg” or if you check system messages you can see this error.

May 28 19:08:26 solaris10.remotehost.com inetd[24233]: [ID 702911 daemon.error] Failed to set credentials for the inetd_start method of instance svc:/network/nrpe/tcp:default (chdir: No such file or directory)
May 28 19:15:27 solaris10.remotehost.com inetd[24241]: [ID 702911 daemon.error] Failed to set credentials for the inetd_start method of instance svc:/network/nrpe/tcp:default (chdir: No such file or directory)

# cd nrpe-2.12; ./configure –with-ssl=/usr/sfw/ –with-ssl-lib=/usr/sfw/lib/ –with-ssl-inc=/usr/sfw/include

Still if you compilation fails please apply these faqs/solutions given in nagios faqs.

http://www.nagios.org/faqs/index.php?section_id=4&expand=false&showdesc=true

In my case I had to make changes in src/nrpe.c for encryption. Do make all, make install to create respective binaries.

# make all; make install; make install-daemon-config;

Once that is done, modify nrpe.cfg with approprite settings. Add following line at the end of /etc/services

nrpe 5666/tcp # NRPE

Also add this line to /etc/inetd.conf and convert it into SMF and enable service with -e option. Also checkout whether it went online.

nrpe stream tcp nowait nagios /usr/sfw/sbin/tcpd /usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -i

# inetconv; inetconv -e

# svcs | grep nrpe

Check if 5666 port is open and in LISTEN mode.

# netstat -a | grep nrpe

Make sure that your /etc/hosts.allow and /etc/hosts.deny does not block your nagios server. Here are the entries

hosts.allow: nrpe: 127.0.0.1, 172.17.38.11

hosts.deny: nrpe: ALL

Final command, make sure that nrpe returns correct output.

# /usr/local/nagios/libexec/check_nrpe -H localhost
NRPE v2.12

Open Audit

2009-06-29T06:30:00.000-07:00

There is no documentation available for this Open Source Tool. These all points written while going through open-audit documentation.

What it Open Audit?
- It audits hardware and software it discovers on the your computer.
- Use's MySQL database to store all discovered data.
- PHP used to display information stored in MySQL database.
- Apache to make it available through web interface.

What is audit.vbs?
- audit.vbs reads data from Microsoft's Windows Management Interface (WMI) and posts its findings to the server.
- OA collects the data using audit.vbs script and write directly to web server through POST method.

Schedule an audit?
- use "at" command to schedule an audit.
- audit domain everyday at some specific time, (can also use windows schedule task)
at 18:00 /interactive /every:M,T,W,Th,F,S,Su "C:\Program Files\xampp\htdocs\scripts\audit_mydomain.bat"
- audit_mydomain.bat contains something like....
@echo off
rem audit local domain pcs
cscript audit.vbs
cscript nmap.vbs
:end

OTRS Issues - Phase I

2009-06-26T00:05:00.000-07:00

Putting it from list.otrs.org for my own information.
-----------------------------------------------------
Problem: How to Clean up the database.?
Solution
- You can use the Generic Agent to remove all or some ticket based on criteria.
- With a bulk change you could set all or some tickets to state 'removed' for instance, and than run GA on it.
- Deleting customers/agents is harder, like for some other data types. You could do it in the database (phpmyadmin), or you can do like I do, recycle. Make them invalid, rename them to INVALID... en reuse (rename) when needed.
--------------------------------------------------------------------------------------

Problem : How to setup LDAP Authentication?
Solution:
#Enable LDAP authentication for Customers / Users
$Self->{'Customer::AuthModule'} = 'Kernel::System::CustomerAuth::LDAP';
$Self->{'Customer::AuthModule::LDAP::Host'} = 'xx.xxx.xx.xx';
$Self->{'Customer::AuthModule::LDAP::BaseDN'} =
'ou=user,ou=dublin,dc=int,dc=domain,dc=com';
$Self->{'Customer::AuthModule::LDAP::UID'} = 'sAMAccountName';

#The following is valid but would only be necessary if the
#anonymous user do NOT have permission to read from the LDAP tree
# $Self->{'Customer::AuthModule::LDAP::SearchUserDN'} = 'otrsldap';
# $Self->{'Customer::AuthModule::LDAP::SearchUserPw'} = 'password';
$Self->{'Customer::AuthModule::LDAP::SearchUserDN'} = 'MyDomain\otrsldap';
$Self->{'Customer::AuthModule::LDAP::SearchUserPw'} = 'password';

#CustomerUser
#(customer user database backend and settings)
$Self->{CustomerUser} = {
Module => 'Kernel::System::CustomerUser::LDAP',
Params => {
Host => 'xx.xxx.xx.xx',
BaseDN => 'ou=user,ou=dublin,dc=int,dc=domain,dc=com',
SSCOPE => 'sub',
UserDN =>'otrsldap',
UserPw => 'password',
},

# customer unique id
CustomerKey => 'sAMAccountName',
# customer #
CustomerID => 'mail',
CustomerUserListFields => ['sAMAccountName', 'cn', 'mail'],
CustomerUserSearchFields => ['sAMAccountName', 'cn', 'mail'],
CustomerUserSearchPrefix => '',
CustomerUserSearchSuffix => '*',
CustomerUserSearchListLimit => 250,
CustomerUserPostMasterSearchFields => ['mail'],
CustomerUserNameFields => ['givenname', 'sn'],
Map => [
# note: Login, Email and CustomerID needed!
# var, frontend, storage, shown, required, storage-type
#[ 'UserSalutation', 'Title', 'title', 1, 0, 'var' ],
[ 'UserFirstname', 'Firstname', 'givenname', 1, 1, 'var' ],
[ 'UserLastname', 'Lastname', 'sn', 1, 1, 'var' ],
[ 'UserLogin', 'Login', 'sAMAccountName', 1, 1, 'var' ],
[ 'UserEmail', 'Email', 'mail', 1, 1, 'var' ],
[ 'UserCustomerID', 'CustomerID', 'mail', 0, 1, 'var' ],
#[ 'UserPhone', 'Phone', 'telephonenumber', 1, 0, 'var' ],
#[ 'UserAddress', 'Address', 'postaladdress', 1, 0, 'var' ],
#[ 'UserComment', 'Comment', 'description', 1, 0, 'var' ],
],
};

#Add the following lines when only users are allowed to login if they
reside in the spicified security group
#Remove these lines if you want to provide login to all users specified in
the User Base DN
#example: $Self->{'Customer::AuthModule::LDAP::BaseDN'} = 'ou=BaseOU,
dc=example, dc=com';
$Self->{'Customer::AuthModule::LDAP::GroupDN'} =
'CN=OTRS_Users,OU=Security Groups,OU=Dublin,DC=int,DC=domain,DC=com';
$Self->{'Customer::AuthModule::LDAP::AccessAttr'} = 'member';
$Self->{'Customer::AuthModule::LDAP::UserAttr'} = 'DN'
--------------------------------------------------------------------------------------

Problem:
Solution:

Few important points about OTRS:
--------------------------------
- The queue view only displays unlocked tickets by default.
- There is a line that says "Tickets shown..... All Tickets xx" The xx is a link which should display all tickets locked and unlocked which are in your "My Queues".

Innodb Error 'Can't create table 'mysql.ibbackup_binlog_marker'

2009-03-16T12:08:00.000-07:00

Problem:
090316 11:57:32 [ERROR] Slave SQL: Error 'Can't create table 'mysql.ibbackup_binlog_marker' (errno: -1)' on query. Default database: 'mysql'. Query: 'CREATE TABLE ibbackup_binlog_marker(a INT) TYPE=INNODB', Error_code: 1005
090316 11:57:32 [Warning] Slave: The syntax 'TYPE=storage_engine' is deprecated and will be removed in MySQL 5.2. Please use 'ENGINE=storage_engine' instead Error_code: 1287
090316 11:57:32 [Warning] Slave: Can't create table 'mysql.ibbackup_binlog_marker' (errno: -1)
Error_code: 1005
090316 11:57:32 [ERROR] Error running query, slave SQL thread aborted. Fix the problem, and restart the slave SQL thread with "SLAVE START". We stopped at log 'testing-bin.000009' position 321

Answer:

mysql> CREATE TABLE ibbackup_binlog_marker2(a INT) TYPE=INNODB;
Query OK, 0 rows affected, 1 warning (0.02 sec)

bash# cd /var/mysql/data/
bash# mv mysql/ibbackup_binlog_marker{2,}.frm
bash# mysqladmin flush-tables

mysql> SET SQL_LOG_BIN = 0;
Query OK, 0 rows affected (0.00 sec)

mysql> DROP TABLE IF EXISTS ibbackup_binlog_marker;
Query OK, 0 rows affected (0.12 sec)

All about : NTP

2009-02-18T08:57:00.000-08:00

I had this plan long back that i will keep my own configurations and documents ready for others to use it. My memory is very short, so i forget things very often. One day i came across this blogger and found best way to keep everything at one place and need not to carry single paper anywhere.

Planning to start All about sessions on all servers, topics etc. Anything which is interesting and information about it is scattered everywhere. hope will be able to do that.

NTP (Network Time Protocol)
---------------------------
What is it ?
Used to synchronize the clocks of computers to some time reference.

NTP uses UDP/IP packets for data transfer because of the fast connection setup and response times.

Port number for the NTP (that ntpd and ntpdate listen and talk to) is 123.

how many ntp servers available in Internet?
According to ntp.org there are 175,000 ntp servers are available in the Internet. Among these there were over 300 valid stratum-1 servers. In addition there were over 20,000 servers at stratum 2, and over 80,000 servers at stratum 3.

ntp commands
ntpd - A daemon process that is both, client and server.
ntpdate - A utility to set the time once, similar to the popular rdate command.
ntpq, ntpdc - Monitoring and control programs that communicate via UDP with ntpd.
ntptrace - A utility to back-trace the current system time, starting from the local server.

time references
- A reference clock is some device or machinery that spits out the current time.
- A reference clock will provide the current time, that's for sure.
- NTP will compute some additional statistical values like offset (or phase), jitter (or dispersion), frequency error, and stability.

There are serveral ways how a NTP client will know about NTP servers to use:
- Servers to be polled can be configured manually
- Servers can send the time directly to a peer
- Servers may send out the time using multicast or broadcast addresses

- ntpd's reaction will depend on the offset between the local clock and the reference time.
- For a tiny offset ntpd will adjust the local clock as usual; for small and larger offsets, ntpd will reject the reference time for a while.
- In the latter case the operation system's clock will continue with the last corrections effective while the new reference time is being rejected.
- After some time, small offsets (significantly less than a second) will be slewed (adjusted slowly), while larger offsets will cause the clock to be stepped (set anew).
- Huge offsets are rejected, and ntpd will terminate itself, believing something very strange must have happened.

stratum 1
A server operating at stratum 1 belongs to the class of best NTP servers available, because it has a reference clock attached to it.

Servers synchronized to a stratum 1 server will be stratum 2.

RRDtool in short....

2008-12-30T22:34:00.000-08:00

Copied notes from: http://oss.oetiker.ch/rrdtool/tut/rrdtutorial.en.html
- RRDtool refers to Round Robin Database tool.
- RRDtool works with with Round Robin Databases (RRDs). It stores and retrieves data from them.
- RRDtool stores all sort of time-series data.
- If you measure some value at several points in time and provide this information to RRDtool. RRDtool will be able to store it.
- RRDtool originated from MRTG.
- RRDtool create graphs in PNG formats.
- We only need sensors to measure the data and able to feed the data into RRDtool.
- Create sample Round Robin Database,
rrdtool create test.rrd --start 920804400 DS:speed:COUNTER:600:U:U RRA:AVERAGE:0.5:1:24 RRA:AVERAGE:0.5:6:10
- Update database,
rrdtool update test.rrd 920804700:12345 920805000:12357 920805300:12363
rrdtool update test.rrd 920805600:12363 920805900:12363 920806200:12373
- fetch data from database,
rrdtool fetch test.rrd AVERAGE --start 920804400 --end 920809200
- "NaN" stands for "Not A Number" - Something is wrong.
- "UNKN" stands for "UNKNOWN", which is ok.
- Create graphics,
rrdtool graph speed.png --start 920804400 --end 920808000 DEF:myspeed=test.rrd:speed:AVERAGE LINE2:myspeed#FF0000

There are several ways for RRDtool to get a rate from its input:
* GAUGE: keep it "as is". The input is already a rate. An example would be a speedometer. This is also the type used for keeping track of temperature and such.

* COUNTER: look at the difference between the previous value and the current value (the delta). An example would be an odometer. The rate is computed as: delta(counter) divided by delta(time).

* ABSOLUTE: as the odometer, but now the counter is reset every time it is read. Computed as: value divided by delta(time).

* DERIVE: as COUNTER, but now it can also go back. An example could be something monitoring a bidirectional pump. The resulting rate can be negative as well as positive.

Redhat Directory Server

2008-12-28T23:20:00.001-08:00

Port Numbers:
- The Directory Server instance (LDAP) has a default port number of 389.
- Administration Server port number has a default number of 9830. If the default port number for either server is in use, then the setup program randomly generates a port number larger than 1024 to use as the default.
- For LDAPS (LDAP with TLS/SSL), the default port number is 636.

Directory Manager:
- Directory Server setup creates a special user called the Directory Manager.
- A unique, powerful entry that is used to administer all user and configuration tasks.
- access controls. password policy, and database limits for size, time, and lookthrough limits do not apply to the Directory Manager.
- It is used only for authentication.
- The Directory Server setup process prompts for a distinguished name (DN) and a password for the Directory Manager.
- The default value for the Directory Manager DN is cn=Directory Manager.

Directory Administrator
- The Directory Administrator is the "super user" that manages all Directory Server and Administration Server instances through the Directory Server Console.

Administration Server User
- By default, the Administration Server runs as the same non-root user as the Directory Server.

There are important differences between the Directory Administrator and the Directory Manager:
* The administrator cannot create top level entries for a new suffix through an add operation. either adding an entry in the Directory Server Console or using ldapadd, a tool provided with OpenLDAP. Only the Directory Manager can add top-level entries by default. To allow other users to add top-level entries, create entries with the appropriate access control statements in an LDIF file, and perform an import or database initialization procedure using that LDIF file.
* Password policies do apply to the administrator, but you can set a user-specific password policy for the administrator.
* Size, time, and lookthrough limits apply to the administrator, but you can set different resource limits for this user.

setup-ds-admin.pl
- The Directory Server and Administration Server instances are created and configured through a script call setup-ds-admin.pl.
- to set the machine name, suffix, and Directory Server port of the new instance, the command is as follows:
/usr/sbin/setup-ds-admin.pl General.FullMachineName=ldap.example.com “slapd.Suffix=dc=example, dc=com” slapd.ServerPort=389
- When the setup-ds-admin.pl finishes, it generates a log file in the /tmp directory called setupXXXXXX.log where XXXXXX is a series of random characters.
-

Difference between innodb and myisam.

2008-12-19T03:01:00.000-08:00

- MyISAM offers speed where as InnoDB offers reliability.
- Innodb support transactions, MyISAM not.
- InnoDB also supports row-level locking, while MyISAM only supports table locking.
- InnoDB is specifically for high volume, high performance.
- With replication it's even possible to take advantage of both storage engines on one table. For example, the master could store a table as InnoDB which makes it fast for INSERTs, UPDATEs and DELETEs while the slave(s) could store the same table as MyISAM and offer the best performance for SELECTs.
-

Limiting closed port RST response from 266 to 200 packets/second.

2008-12-18T21:17:00.000-08:00

Kernel default setting for icmp response is set to 200.
net.inet.icmp.icmplim sysctl limits.

Possible reasons are,
1. This generally means the system is being portscanned or a similar activity on the machine. In worst case someone trying to do DOS attack.
I suggest that you set the following sysctl variables,
net.inet.tcp.blackhole=2
net.inet.udp.blackhole=1

2. But it can also mean that a often-used service on the machine (like http or a database server) is down and you're getting a lot of failed connection requests from clients.

How to find out and terminate or kill the defunct processes?

2008-12-18T21:15:00.000-08:00

lsof | grep "deleted" or
lsof | grep "process" (rather long and messy)

df command shows different used disk space than du.

2008-12-18T21:13:00.000-08:00

If the files are deleted (by rm command) while they are being opened or used by a Linux program / process, the evil of “open file descriptor” problem arises and confuse the Linux file system on reporting the real figure of used disk space or free disk space available.

In order to resolve the fake “disk space full” problem, i.e. to reclaim “used disk space”, you need to kill or terminate the “defunct process” - in this case, the rm command that turns to be defunct process while the files are being used.

Once these defunct processes are terminated, the “open file descriptor” problem will be resolved, and both the du and df commands will agree to report the real file system used disk space or free disk space!

Use remote Linux GUI application tools locally.

2008-12-18T06:10:00.000-08:00

You must have OpenSSH server installed.
Open SSHD configuration file /etc/ssh/sshd_config
$ sudo vi /etc/ssh/sshd_config

Turn on X11Forwarding by setting X11Forwarding parameter to yes:
X11Forwarding yes
Save and close the file.

Restart OpenSSH server you so the changes will take place:
$ sudo /etc/init.d/sshd restart

Logout and close ssh connection.

Running a command remotely
$ ssh -X 203.199.92.106 /usr/bin/gnome-terminal

Another option is to connect to the remote server and use X port forwarding:
$ ssh -X {remote server}

Reference Links:
* Refer to OpenSSH man pages (man sshd, sshd_config, ssh_config)
* VNC - An alternative to X forwarding

Redhat Clustering...

2008-12-17T08:40:00.000-08:00

How Solaris is different from Linux.

2008-12-16T10:13:00.000-08:00

File system structure is same as other *nix. few differences are,
- /usr/adm is symlink to /var/adm which is similar to linux /var/log.
- /usr/sadm - Solaris admin tools like SMC (Solaris management tools)
- /usr/proc - Solaris ptools(process tools) such as pfiles, pmap, pwdx, pstack.
- /usr/X11 - X server and related tools.

Solaris doesnt contain /root directory. Root user shouldnt be doing things which requires /root directory.

In Solaris you will also not find SUDO utility because of RBAC (Role Based Access Control).

In solaris need to add NFS shares to /etc/dfs/dfstab. DFS stands for Distributed File System.

To export filesystems you can edit /etc/dfs/dfstab and run exportfs -a (or svcadm restart svc:/network/nfs/server) or you can use the share command. share allows you to quickly export a filesystem, so if you wanted to NFS share /opt you could just execute share /opt and your done.

Solaris doesn't have top. But, we have something better yet similar: prstat.

you can use the Solaris "ptools" (process tools) to learn more about a process, such as pstack `pgrep cron` to see the call stack of the cron process, or pfiles `pgrep firefox-bin` to see details about every file that Firefox has open.

Packages come in two varieties: filesystem format and datastream.
- A filesystem format package is what you'll find on Sun CD's and is really just a directory stucture containing all the various elements and files of the package.
- A datastream package is a filesystem format package thats rolled into a single file making it easy to compress and distribute over the net. Packages use a common naming convension of ORGsoftware, such as SUNWspro

Both types of packages are installed using the pkgadd command (ie: pkgadd -d ./CUDLgcc-4.0.1.pkg for datastream and pkgadd -d . for filesystem format).

Use svcs to view services, svcadm to administer them (start, stop, etc), and svccfg to add or change them.

SMF services are described in XML manifests, find the default system manifests in /var/svc/manifest. Manifests describe a service, what its dependancies are, supply optional metadata, and provide methods to start, stop, refresh, or restart a service.

The standard Solaris naming convension for disks is: c0t0d0s0, that is to say: controller 0, target 0, LUN 0, slice 0.

TCP and UDP Ports.

2008-08-26T04:21:00.000-07:00

Reference : http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers

The port numbers are divided into three ranges:
* The Well Known Ports are those in the range 0–1023. On Unix-like operating systems, opening a port in this range to receive incoming connections requires administrative privileges or possessing CAP_NET_BIND_SERVICE capability.

* The Registered Ports are those in the range 1024–49151.

* The Dynamic and/or Private Ports are those in the range 49152–65535. Randomly chosen port numbers out of this range are called ephemeral ports. These ports are not permanently assigned to any publicly defined application.

My Mysql Notes....

2008-08-20T22:00:00.000-07:00

Will start soon......

grep, egrep and fgrep from manpage

2008-08-20T12:59:00.000-07:00

grep
grep searches the named input FILEs (or standard input if no files are named, or if a single hyphen-minus (-) is given as file name) for lines containing a match to the given PATTERN. By default, grep prints the matching lines.

egrep
-E, --extended-regexp
Interpret PATTERN as an extended regular expression (ERE, see below).

fgrep
-F, --fixed-strings
Interpret PATTERN as a list of fixed strings, separated by newlines, any of which is to be matched.

Important Options with grep :
-R, -r, --recursive
Read all files under each directory, recursively; this is equivalent to the -d recurse option.
--exclude-dir=DIR
Exclude directories matching the pattern DIR from recursive searches.
-A NUM, --after-context=NUM
Print NUM lines of trailing context after matching lines. Places a line containing a group separator (--) between contiguous groups of matches. With the -o or --only-matching option, this has no effect and a warning is given.
-B NUM, --before-context=NUM
Print NUM lines of leading context before matching lines. Places a line containing a group separator (--) between contiguous groups of matches. With the -o or --only-matching option, this has no effect and a warning is given.
-n, --line-number
Prefix each line of output with the 1-based line number within its input file.
-c, --count
Suppress normal output; instead print a count of matching lines for each input file.
-i, --ignore-case
Ignore case distinctions in both the PATTERN and the input files.

egrep is the same as grep -E.
fgrep is the same as grep -F.
rgrep is the same as grep -r.

grep Repetition
A regular expression may be followed by one of several repetition operators:
? The preceding item is optional and matched at most once.
* The preceding item will be matched zero or more times.
+ The preceding item will be matched one or more times.
{n} The preceding item is matched exactly n times.
{n,} The preceding item is matched n or more times.
{,m} The preceding item is matched at most m times.
{n,m} The preceding item is matched at least n times, but not more than m times.

Sed One liners....

2008-08-19T08:34:00.000-07:00

Reference : http://sed.sourceforge.net/sed1line.txt

FILE SPACING:
# double space a file
sed G

# double space a file which already has blank lines in it. Output file
# should contain no more than one blank line between lines of text.
sed '/^$/d;G'

# triple space a file
sed 'G;G'

# undo double-spacing (assumes even-numbered lines are always blank)
sed 'n;d'

# insert a blank line above every line which matches "regex"
sed '/regex/{x;p;x;}'

# insert a blank line below every line which matches "regex"
sed '/regex/G'

# insert a blank line above and below every line which matches "regex"
sed '/regex/{x;p;x;G;}'

NUMBERING:

# number each line of a file (simple left alignment). Using a tab (see
# note on '\t' at end of file) instead of space will preserve margins.
sed = filename | sed 'N;s/\n/\t/'

# number each line of a file (number on left, right-aligned)
sed = filename | sed 'N; s/^/ /; s/ *$.\{6,\}$\n/\1 /'

# number each line of file, but only print numbers if line is not blank
sed '/./=' filename | sed '/./N; s/\n/ /'

# count lines (emulates "wc -l")
sed -n '$='

TEXT CONVERSION AND SUBSTITUTION:

# IN UNIX ENVIRONMENT: convert DOS newlines (CR/LF) to Unix format.
sed 's/.$//' # assumes that all lines end with CR/LF
sed 's/^M$//' # in bash/tcsh, press Ctrl-V then Ctrl-M
sed 's/\x0D$//' # works on ssed, gsed 3.02.80 or higher

# IN UNIX ENVIRONMENT: convert Unix newlines (LF) to DOS format.
sed "s/$/`echo -e \\\r`/" # command line under ksh
sed 's/$'"/`echo \\\r`/" # command line under bash
sed "s/$/`echo \\\r`/" # command line under zsh
sed 's/$/\r/' # gsed 3.02.80 or higher

# IN DOS ENVIRONMENT: convert Unix newlines (LF) to DOS format.
sed "s/$//" # method 1
sed -n p # method 2

# IN DOS ENVIRONMENT: convert DOS newlines (CR/LF) to Unix format.
# Can only be done with UnxUtils sed, version 4.0.7 or higher. The
# UnxUtils version can be identified by the custom "--text" switch
# which appears when you use the "--help" switch. Otherwise, changing
# DOS newlines to Unix newlines cannot be done with sed in a DOS
# environment. Use "tr" instead.
sed "s/\r//" infile >outfile # UnxUtils sed v4.0.7 or higher
tr -d \r outfile # GNU tr version 1.22 or higher

# delete leading whitespace (spaces, tabs) from front of each line
# aligns all text flush left
sed 's/^[ \t]*//' # see note on '\t' at end of file

# delete trailing whitespace (spaces, tabs) from end of each line
sed 's/[ \t]*$//' # see note on '\t' at end of file

# delete BOTH leading and trailing whitespace from each line
sed 's/^[ \t]*//;s/[ \t]*$//'

# insert 5 blank spaces at beginning of each line (make page offset)
sed 's/^/ /'

# align all text flush right on a 79-column width
sed -e :a -e 's/^.\{1,78\}$/ &/;ta' # set at 78 plus 1 space

# center all text in the middle of 79-column width. In method 1,
# spaces at the beginning of the line are significant, and trailing
# spaces are appended at the end of the line. In method 2, spaces at
# the beginning of the line are discarded in centering the line, and
# no trailing spaces appear at the end of lines.
sed -e :a -e 's/^.\{1,77\}$/ & /;ta' # method 1
sed -e :a -e 's/^.\{1,77\}$/ &/;ta' -e 's/$ *$\1/\1/' # method 2

# substitute (find and replace) "foo" with "bar" on each line
sed 's/foo/bar/' # replaces only 1st instance in a line
sed 's/foo/bar/4' # replaces only 4th instance in a line
sed 's/foo/bar/g' # replaces ALL instances in a line
sed 's/$.*$foo$.*foo$/\1bar\2/' # replace the next-to-last case
sed 's/$.*$foo/\1bar/' # replace only the last case

# substitute "foo" with "bar" ONLY for lines which contain "baz"
sed '/baz/s/foo/bar/g'

# substitute "foo" with "bar" EXCEPT for lines which contain "baz"
sed '/baz/!s/foo/bar/g'

# change "scarlet" or "ruby" or "puce" to "red"
sed 's/scarlet/red/g;s/ruby/red/g;s/puce/red/g' # most seds
gsed 's/scarlet\|ruby\|puce/red/g' # GNU sed only

# reverse order of lines (emulates "tac")
# bug/feature in HHsed v1.5 causes blank lines to be deleted
sed '1!G;h;$!d' # method 1
sed -n '1!G;h;$p' # method 2

# reverse each character on the line (emulates "rev")
sed '/\n/!G;s/$.$$.*\n$/&\2\1/;//D;s/.//'

# join pairs of lines side-by-side (like "paste")
sed '$!N;s/\n/ /'

# if a line ends with a backslash, append the next line to it
sed -e :a -e '/\\$/N; s/\\\n//; ta'

# if a line begins with an equal sign, append it to the previous line
# and replace the "=" with a single space
sed -e :a -e '$!N;s/\n=/ /;ta' -e 'P;D'

# add commas to numeric strings, changing "1234567" to "1,234,567"
gsed ':a;s/\B[0-9]\{3\}\>/,&/;ta' # GNU sed
sed -e :a -e 's/$.*[0-9]$$[0-9]\{3\}$/\1,\2/;ta' # other seds

# add commas to numbers with decimal points and minus signs (GNU sed)
gsed -r ':a;s/(^|[^0-9.])([0-9]+)([0-9]{3})/\1\2,\3/g;ta'

# add a blank line every 5 lines (after lines 5, 10, 15, 20, etc.)
gsed '0~5G' # GNU sed only
sed 'n;n;n;n;G;' # other seds

SELECTIVE PRINTING OF CERTAIN LINES:

# print first 10 lines of file (emulates behavior of "head")
sed 10q

# print first line of file (emulates "head -1")
sed q

# print the last 10 lines of a file (emulates "tail")
sed -e :a -e '$q;N;11,$D;ba'

# print the last 2 lines of a file (emulates "tail -2")
sed '$!N;$!D'

# print the last line of a file (emulates "tail -1")
sed '$!d' # method 1
sed -n '$p' # method 2

# print the next-to-the-last line of a file
sed -e '$!{h;d;}' -e x # for 1-line files, print blank line
sed -e '1{$q;}' -e '$!{h;d;}' -e x # for 1-line files, print the line
sed -e '1{$d;}' -e '$!{h;d;}' -e x # for 1-line files, print nothing

# print only lines which match regular expression (emulates "grep")
sed -n '/regexp/p' # method 1
sed '/regexp/!d' # method 2

# print only lines which do NOT match regexp (emulates "grep -v")
sed -n '/regexp/!p' # method 1, corresponds to above
sed '/regexp/d' # method 2, simpler syntax

# print the line immediately before a regexp, but not the line
# containing the regexp
sed -n '/regexp/{g;1!p;};h'

# print the line immediately after a regexp, but not the line
# containing the regexp
sed -n '/regexp/{n;p;}'

# print 1 line of context before and after regexp, with line number
# indicating where the regexp occurred (similar to "grep -A1 -B1")
sed -n -e '/regexp/{=;x;1!p;g;$!N;p;D;}' -e h

# grep for AAA and BBB and CCC (in any order)
sed '/AAA/!d; /BBB/!d; /CCC/!d'

# grep for AAA and BBB and CCC (in that order)
sed '/AAA.*BBB.*CCC/!d'

# grep for AAA or BBB or CCC (emulates "egrep")
sed -e '/AAA/b' -e '/BBB/b' -e '/CCC/b' -e d # most seds
gsed '/AAA\|BBB\|CCC/!d' # GNU sed only

# print paragraph if it contains AAA (blank lines separate paragraphs)
# HHsed v1.5 must insert a 'G;' after 'x;' in the next 3 scripts below
sed -e '/./{H;$!d;}' -e 'x;/AAA/!d;'

# print paragraph if it contains AAA and BBB and CCC (in any order)
sed -e '/./{H;$!d;}' -e 'x;/AAA/!d;/BBB/!d;/CCC/!d'

# print paragraph if it contains AAA or BBB or CCC
sed -e '/./{H;$!d;}' -e 'x;/AAA/b' -e '/BBB/b' -e '/CCC/b' -e d
gsed '/./{H;$!d;};x;/AAA\|BBB\|CCC/b;d' # GNU sed only

# print only lines of 65 characters or longer
sed -n '/^.\{65\}/p'

# print only lines of less than 65 characters
sed -n '/^.\{65\}/!p' # method 1, corresponds to above
sed '/^.\{65\}/d' # method 2, simpler syntax

# print section of file from regular expression to end of file
sed -n '/regexp/,$p'

# print section of file based on line numbers (lines 8-12, inclusive)
sed -n '8,12p' # method 1
sed '8,12!d' # method 2

# print line number 52
sed -n '52p' # method 1
sed '52!d' # method 2
sed '52q;d' # method 3, efficient on large files

# beginning at line 3, print every 7th line
gsed -n '3~7p' # GNU sed only
sed -n '3,${p;n;n;n;n;n;n;}' # other seds

# print section of file between two regular expressions (inclusive)
sed -n '/Iowa/,/Montana/p' # case sensitive

SELECTIVE DELETION OF CERTAIN LINES:

# print all of file EXCEPT section between 2 regular expressions
sed '/Iowa/,/Montana/d'

# delete duplicate, consecutive lines from a file (emulates "uniq").
# First line in a set of duplicate lines is kept, rest are deleted.
sed '$!N; /^$.*$\n\1$/!P; D'

# delete duplicate, nonconsecutive lines from a file. Beware not to
# overflow the buffer size of the hold space, or else use GNU sed.
sed -n 'G; s/\n/&&/; /^$[ -~]*\n$.*\n\1/d; s/\n//; h; P'

# delete all lines except duplicate lines (emulates "uniq -d").
sed '$!N; s/^$.*$\n\1$/\1/; t; D'

# delete the first 10 lines of a file
sed '1,10d'

# delete the last line of a file
sed '$d'

# delete the last 2 lines of a file
sed 'N;$!P;$!D;$d'

# delete the last 10 lines of a file
sed -e :a -e '$d;N;2,10ba' -e 'P;D' # method 1
sed -n -e :a -e '1,10!{P;N;D;};N;ba' # method 2

# delete every 8th line
gsed '0~8d' # GNU sed only
sed 'n;n;n;n;n;n;n;d;' # other seds

# delete lines matching pattern
sed '/pattern/d'

# delete ALL blank lines from a file (same as "grep '.' ")
sed '/^$/d' # method 1
sed '/./!d' # method 2

# delete all CONSECUTIVE blank lines from file except the first; also
# deletes all blank lines from top and end of file (emulates "cat -s")
sed '/./,/^$/!d' # method 1, allows 0 blanks at top, 1 at EOF
sed '/^$/N;/\n$/D' # method 2, allows 1 blank at top, 0 at EOF

# delete all CONSECUTIVE blank lines from file except the first 2:
sed '/^$/N;/\n$/N;//D'

# delete all leading blank lines at top of file
sed '/./,$!d'

# delete all trailing blank lines at end of file
sed -e :a -e '/^\n*$/{$d;N;ba' -e '}' # works on all seds
sed -e :a -e '/^\n*$/N;/\n$/ba' # ditto, except for gsed 3.02.*

# delete the last line of each paragraph
sed -n '/^$/{p;h;};/./{x;/./p;}'

SPECIAL APPLICATIONS:

# remove nroff overstrikes (char, backspace) from man pages. The 'echo'
# command may need an -e switch if you use Unix System V or bash shell.
sed "s/.`echo \\\b`//g" # double quotes required for Unix environment
sed 's/.^H//g' # in bash/tcsh, press Ctrl-V and then Ctrl-H
sed 's/.\x08//g' # hex expression for sed 1.5, GNU sed, ssed

# get Usenet/e-mail message header
sed '/^$/q' # deletes everything after first blank line

# get Usenet/e-mail message body
sed '1,/^$/d' # deletes everything up to first blank line

# get Subject header, but remove initial "Subject: " portion
sed '/^Subject: */!d; s///;q'

# get return address header
sed '/^Reply-To:/q; /^From:/h; /./d;g;q'

# parse out the address proper. Pulls out the e-mail address by itself
# from the 1-line return address header (see preceding script)
sed 's/ *(.*)//; s/>.*//; s/.*[:<] *//'

# add a leading angle bracket and space to each line (quote a message)
sed 's/^/> /'

# delete leading angle bracket & space from each line (unquote a message)
sed 's/^> //'

# remove most HTML tags (accommodates multiple-line tags)
sed -e :a -e 's/<[^>]*>//g;/

Sun Solaris useful sites.

2008-08-15T12:35:00.001-07:00

Here are some of the websites of interest:

http://training.sun.com/US/certification/objectives/index.html
http://training.sun.com/US/certification/solaris/sysadmin.html
http://suned.sun.com/US/certification
http://www.networkessentials.com/certified/sca/
http://www.suncert.com
http://www.informit.com/examcram2/
http://www.learnsolaris.com/v3/index.php
http://www.examslam.com
http://www.unixcert.net/solaris/solaris.htm
http://www.adminschoice.com

HTTP Response Codes

2008-08-07T04:06:00.001-07:00

The following are webserver response codes that are used by webservers of all platforms.

Code Description

100 Continue
101 Switching protocols
200 OK
201 Created
202 Accepted
203 Non-authoritative information
204 No content
205 Reset content
206 Partial content
300 Multiple choices
301 Moved permanently
302 Moved temporarily
303 See other
304 Not modified
305 Use proxy
307 Temporary redirect
400 Bad request
401 Unauthorized
402 Payment required
403 Forbidden
404 Not Found
405 Method not allowed
406 Not acceptable
407 Proxy authentication required
408 Request timeout
409 Conflict
410 Gone
411 Length required
412 Precondition failed
413 Request entity too large
414 Request URI too large
415 Unsupported media type
416 Requested range not satisfiable
417 Expectation failed
500 Internal server error
501 Not implemented
502 Bad gateway
503 Service unavailable
504 Gateway timeout
505 HTTP version not supported

What is Netcat?

2008-08-07T03:41:00.000-07:00

Netcat is a featured networking utility which reads and writes data across network connections, using the TCP/IP protocol.

It is designed to be a reliable "back-end" tool that can be used directly or easily driven by other programs and scripts. At the same time, it is a feature-rich network debugging and exploration tool, since it can create almost any kind of connection you would need and has several interesting built-in capabilities.

It provides access to the following main features:
- Outbound and inbound connections, TCP or UDP, to or from any ports.
- Featured tunneling mode which allows also special tunneling such as UDP to TCP, with the possibility of specifying all network parameters (source port/interface, listening port/interface, and the remote host allowed to connect to the tunnel.
- Built-in port-scanning capabilities, with randomizer.
- Advanced usage options, such as buffered send-mode (one line every N seconds), and hexdump (to stderr or to a specified file) of trasmitted and received data.
- Optional RFC854 telnet codes parser and responder.

Some of the potential uses of netcat:
Script backends
Scanning ports and inventorying services
Backup handlers
File transfers
Server testing and simulation
Firewall testing
Proxy gatewaying
Network performance testing
Address spoofing tests
Protecting X servers

Transferring files using netcat:
When we want to send a file from a host to another with netcat, it is quite simple. We set up the receiving host to listen on a specific port and put all the data received into a file. We need to set a timeout so the listener notices when there is no more data coming and it can close gracefully.

-l = listens for incoming connections
-p = what port to listen on
-v = verbosity level, use twice for more information
-w = timeout
-n = dont resolve IPs

On the senders end we simply connect to the receivers listening port and give the file as input. The filetransfer goes smoothly as long as you remember to initiate the sending before the timeout.

Listener: nc -vvn -l -p 3000 -w 3 > file

Sender: nc -vvn xxx.xxx.xxx.xx 3000 <>

Netcat Commands

Netcat also know as the swiss army knife of network tools, provides a plethora of functions that can be used for good as well as motives that are negative.

What is network latency ?

2008-08-07T01:46:00.000-07:00

If you have a WAN, then one very important concern should be latency. Latency, in this case, is the time that a package of information takes to reach the other end of the slow link. This package of information could be a DNS query, ping, file, or a transaction in a client/server application. Notice that the package of information has not fully arrived at the destination until all bits have arrived. It is often tempting to assume that the only variable here is the bandwidth. It seems logical that the fatter the pipe, the quicker the information package will arrive at its destination. For a large file, latency doesn't play much of a part; however, in the case of small packages like a DNS query, ping, or a transaction, latency can kill your performance. It is very important to distinguish between bandwidth and latency.

Bandwidth is the capacity of the link to transfer quantities of information in a given amount of time. A 128k link can transfer roughly 13 k bytes of information in one second. This can vary depending on compression and other factors. For a 13 meg file, the total time to transfer the file across the link would be 1000 seconds. This doesn't vary that much between different kinds of slow links: frame, ppp, ISDN, etc. This gets interesting, though, when you consider that there are many packages of information that are relatively small. Different slow links have different latency characteristics. Further, as these slow links get loaded down with many different kinds of network traffic, latency can go up quickly.

- ping

- traceroute ( Uses ping command )

What is GDB (GNU Debugger)

2008-08-04T02:17:00.000-07:00

Its GNU Debugger.

The purpose of a debugger such as gdb is to allow you to see what is going on “inside” another program while it executes—or what another program was doing at the moment it crashed.

gdb can do four main kinds of things (plus other things in support of these) to help you catch bugs in the act:
• Start your program, specifying anything that might affect its behavior.
• Make your program stop on specified conditions.
• Examine what has happened, when your program has stopped.
• Change things in your program, so you can experiment with correcting the effects of one bug and go on to learn about another.

Unix Command - mail

2008-07-25T03:15:00.000-07:00

INTRODUCTION

Mail is an intelligent mail processing system, which has a command syntax reminiscent of ed1 with lines replaced by messages.

-v: Verbose mode. The details of delivery are displayed on the user's terminal.
-i: Ignore tty interrupt signals. This is particularly useful when using mail on noisy phone lines.
-I: Forces mail to run in interactive mode even when input isn't a terminal. In particular, the `~ ' special character when sending mail is only active in interactive mode.
-n: Inhibits reading /etc/mail.rc upon startup.
-N: Inhibits the initial display of message headers when reading mail or editing a mail folder.
-s: Specify subject on command line (only the first argument after the -s flag is used as a subject; be careful to quote subjects containing spaces.)
-c: Send carbon copies to list of users.
-b: Send blind carbon copies to list List should be a comma-separated list of names.
-f: Read in the contents of your mbox (or the specified file) for processing; when you quit mail writes undeleted messages back to this file.
-u: Is equivalent to:

mail -f /var/spool/mail/user

Sending mail

To send a message to one or more people, mail can be invoked with arguments which are the names of people to whom the mail will be sent. You are then expected to type in your message, followed by an `control-D ' at the beginning of a line. The section below Replying to or originating mail describes some features of mail available to help you compose your letter.

Reading mail

In normal usage mail is given no arguments and checks your mail out of the post office, then prints out a one line header of each message found. The current message is initially the first message (numbered 1) and can be printed using the print command (which can be abbreviated `p ' ) . You can move among the messages much as you move between lines in ed1, with the commands `+ ' and `- ' moving backwards and forwards, and simple numbers.

Disposing of mail.

After examining a message you can delete `d ' ) the message or reply `r ' ) to it. Deletion causes the mail program to forget about the message. This is not irreversible; the message can be undeleted `u ' ) by giving its number, or the mail session can be aborted by giving the exit `x ' ) command. Deleted messages will, however, usually disappear never to be seen again.

Specifying messages

Commands such as print and delete can be given a list of message numbers as arguments to apply to a number of messages at once. Thus ``delete 1 2 '' deletes messages 1 and 2, while ``delete 1-5 '' deletes messages 1 through 5. The special name `* ' addresses all messages, and `$ ' addresses the last message; thus the command top which prints the first few lines of a message could be used in ``top * '' to print the first few lines of all messages.

Replying to or originating mail.

You can use the reply command to set up a response to a message, sending it back to the person who it was from. Text you then type in, up to an end-of-file, defines the contents of the message. While you are composing a message, mail treats lines beginning with the character `~ ' specially. For instance, typing `~m ' (alone on a line) will place a copy of the current message into the response right shifting it by a tabstop (see indentprefix variable, below). Other escapes will set up subject fields, add and delete recipients to the message and allow you to escape to an editor to revise the message or to a shell to run some commands. (These options are given in the summary below.)

Ending a mail processing session.

You can end a mail session with the quit `q ' ) command. Messages which have been examined go to your mbox file unless they have been deleted in which case they are discarded. Unexamined messages go back to the post office. (See the -f option above).