Wednesday, November 2, 2011

User and Group administration in AIX


User creation

Syntax:

mkuser

Example:

mkuser id=234 pgrp=aix su=true home=/home/abc gecos=”aix admin” abc

The same can be done by using smitty.

Changing user attributes

Syntax:

chuser

Example:

chuser gecos=”AIX team member” abc


Listing user attributes

Syntax:

lsuser (or) lsuser –f

Example:

lsuser –f abc

It will show you all the attributes of the user abc.

If you want to compare the attributes of two users, use the flag –c instead of –f followed by the user names.

lsuser –c abc, xyz

Changing shell of the user

Syntax:

chsh

Example:

chsh abc

It will show you the list of available shells. Type Yes then give the new shell.

Setting password to the username

Syntax:

passwd

Example:

passwd abc
Changing password for “abc”
abc’s new password:
Enter the new password again:

We can also use the command pwdadm to change the password.

Example: pwdadm

Note that the syntax is same as passwd command.

Deleting users

Syntax:

rmuser –p

Example:

rmuser –p abc

It will remove the user id from the server along with the password information.

Similarly general commands used for group activities are as follows.

To create a group

mkgroup

Example: mkgroup aixadmin

To change group properties

chgroup 

Example: chgroup users=sam,ram aixadmin

To delete a group

rmgroup

We can use –p flag to remove the key store values of a group and –R to remove the ldap information.

Example: rmgroup aixadmin

For detailed information, please go through the below link.






Saturday, October 29, 2011


Changing LV name online

Yes. We can change the LV name online in AIX 6.1 TL4.
Usually we will unmount the LV to rename it. But AIX 6.1 TL4 helps us to change the name of the logical volume online.

Steps:

1) Check the oslevel that it is in 6.1 TL4 (Just to ensure).

# oslevel -s
6100-04-01-0944

2) Note down the original LV name

# df -m /home/nmon
Filesystem    MB blocks      Free %Used    Iused %Iused Mounted on
/dev/nmonlv      256.00    254.73    1%       23     1% /home/nmon

# lsvg -l rootvg | grep nmon
nmonlv              jfs2       1       1       1    open/syncd    /home/nmon

3) Now, change the LV name without unmounting it.

# chlv -n nmon_lv nmonlv

Note that df output will not show us any change until we remount the file system. But we can see the new LV name in /etc/filesystems and “lsvg –l rootvg” outputs.

# df -m /home/nmon
Filesystem    MB blocks      Free %Used    Iused %Iused Mounted on
/dev/nmonlv      256.00    254.73    1%       23     1% /home/nmon

# lsvg -l rootvg | grep nmon
nmon_lv             jfs2       1       1       1    open/syncd    /home/nmon

# grep -p nmon /etc/filesystems
/home/nmon:
        dev             = /dev/nmon_lv
        vfs             = jfs2
        log             = /dev/hd8
        mount           = true
        options         = rw
        account         = false
        quota           = no

4) After remounting the filesystem, the df command now displayed the new LV name. 

# umount /home/nmon
# mount /home/nmon
# df /home/nmon
Filesystem    512-blocks      Free %Used    Iused %Iused Mounted on
/dev/nmon_lv      524288    521696    1%       23     1% /home/nmon

Wednesday, October 27, 2010

AIX OS Migration procedure


AIX OS UPGRADATION PROCEDURE

Pre-migration

1)     Check with the application teams, If the new version is compatible for the application to be run fine.
2)     If veritas volume manager is running for managing the application volumes, check with Symantec whether any additional drivers needs to be installed.
3)     Similarly check with the backup team if there is any concern.
4)     Inform the hands on support to have the CD/DVDs available.
5)     If there is any monitoring tool, un configure them.
6)     Take all the configuration details
7)     Take alt clone, mksysb

Migration activity

1)     Ask the hands on person to insert the OS migration CD/DVD to the drive
2)     Reboot the system (or) down and restart it
3)     Go to the SMS menu
4)     Reboot the server through CD/DVD drive

click on the image to enlarge



Note:
The method of installation should be Migration
Some times, It will not show the right disk name in the field ”Disk where you want to install”. So it is better to check with the configuration details for identity. Probably lsdev | grep –i disk can help here.

Once you selected the options press “0” and enter to proceed with the installation.

click on the image to enlarge


Here type F1 and enter. If it is asking the terminal type, you need to give vt100 and press enter immediately.

If you want to enable additional options such as TCB, you need to select for More options (3) as shown in the first figure.

Then it will ask you to save the settings and proceed with the current settings as below.
click on the image to enlarge



Once you give 0 and enter, It will start to install the filesets. It will take around 1 and a half hours to complete. At the end, It will ask you the License agreement. Select yes and proceed.

Once the installation is successful, It is advisable to check the configuration settings and make sure If all are perfect.

Ask the application team, TSM team If they are facing any issues.

Wait for a week or twice, then remove the cone vg and take a fresh clone and mksysb.


Thursday, May 7, 2009

File system types in AIX


In AIX 5.3, there are four types of file systems. They are listed below.

Journaled file system
Enhanced Journal file system
Network file system
CD-ROM file system

Journaled file system
This uses some journaling techniques. So that it is called as Journaled file system. Its acronym is JFS. Each jfs will be residing in a logical volume. So that we can say that the size of the file system will be in terms of logical partitions.

Enhanced Journaled file system
It resides on a jfs2 file system. This will be created when the operating system is installed with the default options. It is the enhanced version of the initial jfs.

Network file system
It is a kind of distributed file system in which all the users can access the files and directories in a common network.

CD-ROM file system
This file system is used to access the contents of the CD ROM.

Wednesday, May 6, 2009

IBM P System Administration test information


IBM offers a System P Administration exam. The exam code has been changed from 000-222 to 000-223. For preparing the certification, you can use the certification guide from the IBM which has been published in the form of Redbooks. You can avail the Redbook for the certification exam 000-222 and there is no Redbook for 000-223. But it is helpful when read the 222 certification guide.

The following link will provide you the Redbook link.

http://www.redbooks.ibm.com/abstracts/sg247199.html

The syllabi for the 000-223 exam can be viewed from the following link.

http://www-03.ibm.com/certify/tests/obj223.shtml

Dumps can be get from the following link

http://www.examcollection.com/

http://www.testkink.com/

http://www.actualtests.com/

Fixing a full var file system

Here I listed some of the ways to fix a var file system.

Step 1:

Check for the large files that might be removed in the /var directory using the find command.

Step 2:

Check the /var/adm/wtmp for the logs of all logins, remote logins. If needed copy the contents of this file and clear it.
#cp /dev/null /var/adm/wtmp

Step 3:

Then clear the error log. Do not use the /dev/null file to clear the error log. Use the following procedure to clear the error log var/adm/ras.

#/usr/lib/errstop

#rm /var/adm/ras/errlog

#/usr/lib/errdemon

Step 4:

If /var/adm/ras/trcfile file is large and the trace is not currently running, we can remove it by

#rm /var/adm/ras/trcfile

Step 5:

Clear the vmcore files from the /var/adm/ras directory

Step 6:

Clear the queueing subsystem files from the /var/spool directory.

Step 7:

Check the /var/preserve directory for terminated vi sessions. It is safety to remove these files.

Fixing var file system


Here I listed some of the ways to fix a var file system.

Step 1:

Check for the large files that might be removed in the /var directory using the find command.

Step 2:

Check the /var/adm/wtmp for the logs of all logins, remote logins. If needed copy the contents of this file and clear it.
#cp /dev/null /var/adm/wtmp

Step 3:

Then clear the error log. Do not use the /dev/null file to clear the error log. Use the following procedure to clear the error log var/adm/ras.

#/usr/lib/errstop

#rm /var/adm/ras/errlog

#/usr/lib/errdemon

Step 4:

If /var/adm/ras/trcfile file is large and the trace is not currently running, we can remove it by

#rm /var/adm/ras/trcfile

Step 5:

Clear the vmcore files from the /var/adm/ras directory

Step 6:

Clear the queueing subsystem files from the /var/spool directory.

Step 7:

Check the /var/preserve directory for terminated vi sessions. It is safety to remove these files.