Fixing a full root file system

Step 1:

Read the contents of the /etc/security/failedlogin and if needed, backup the content of this file. Then remove the entries by using the following command.

#cp /dev/null /etc/security/failedlogin

Step 2:

Check the /dev directory. If there is any duplicate entry i.e. invalid device names (for ex. rmto instead of rmt0), remove it.

Step 3:

Check for very large files that might be removed. This can be done by using find command.

Before removing the large files, check whether the file is currently being used by the user. This can be done by the fuser filename command.

LVM and User administration commands on aix

LVM commands

1. Adding LUN.

#extendvg vg name pv name

2. creating Volume Group.

#mkvg –y vg name physical volume

3. creating Logical volume.

#mklv –y lv name -t file system volume group number of LP physical volume


4. creating file system.

#crfs –v file system type -g volume group -a size= size in M -m mt point

5. increasing & Decreasing file system.

#chfs -a size= +4194304 MOUNT_POINT

#chfs -a size=-16M MOUNT POINT

6. file integrating checking.

#fsck file

7. mount /umount the file systems.

# mount /dev/fslv02 /test
# umount /test

8. File permission /ownership changes.

#chmod u=permission,g=permission,o=permission file
#chown –R owner:group file

9. Rootvg mirroring

#mirrorvg rootvg new and empty pv

OR

#mklvcopy lvname copy pv


User Administration Commands

1) Create the user

To create the user account with the default values in /usr/lib/security/mkuser.default

#mkuser username

To create the user account as an administrator

#mkuser –a username

2) Remove the user

To remove the user from the local system

#rmuser username

To remove the user with its attributes including user authentication information.,

#rmuser –p username

3) To reset a password

#passwd username

4) To unlock the user Id

#chuser “account_locked=false” userid

5) To set a non expiry password for the user

#chsec –f /etc/security/user –a maxage=0

6) To change the characteristics of the user

#chuser –a attribute=value