How to reduce /tmp or /var in V4.3?

NOTE: Back up the data before proceeding. If you have a tape drive connected to your RS/6000, this can be achieved by executing the following sequence of commands on either /var or /tmp:
cd /
tar -cvf /dev/rmt0 /var
/dev/rmt0 can be replaced with /dev/fd0 or the full path of a directory NOT in the same file system.

1. Boot your system into a limited function maintenance shell (Service or Maintenance mode) from bootable AIX media.
Please refer to your system user@#s or installation and service guide for specific IPL procedures related to your type and model of RS/6000.

2. With bootable media of the same version and level as the system, boot the system into Service mode.
The bootable media can be any ONE of the following:
Bootable CD-ROM
NON_AUTOINSTALL, bootable mksysb
Bootable Install Tape
Follow the screen prompts or icons to the Welcome to Base OS menu.
a.Choose Start Maintenance Mode for System Recovery (Option 3). The next screen displays prompts for the Maintenance menu.
b.Choose Aclearcase/" target="_blank" >ccess a Root Volume Group (Option 1).
The next screen displays a warning that indicates you will not be able to return to the Base OS menu without rebooting.
c.Choose 0 continue.
The next screen displays information about all volume groups on the system.
d.Select the root volume group by number. The logical volumes in rootvg will be displayed with two options below.
e.Choose Access this volume group and start a shell. (Option 1).
If you get errors from the preceding option, do not continue with this procedure. Correct the problem causing the error. If you need assistance correcting the problem causing the error, contact IBM 800-810-1818 or your AIX service provider.
If no errors occur, proceed with the following steps.
3. Unmount the file system. (The following examples use /var. If you intend to reduce the /tmp file system, substitute /tmp for /var in the commands.) Execute:
umount /var
4. Remove the file system by executing:
rmfs /var
5. Determine the physical partition (PP) size of your rootvg volume group with the command:
lsvg rootvg
6. Create the logical volume with one of these commands:
mklv -y hd9var rootvg [x] (for /var)
mklv -y hd3 rootvg [x] (for /tmp)
x is the number of logical partitions you want to allocate. If your rootvg volume group has a PP size of 32MB, and you want the /var file system to be a total of 128MB in size, then x would be 4. For example:
mklv -y hd9var rootvg 4
This command makes a logical volume hd9var of size 128MB (four 32MB partitions) in the rootvg volume group.
NOTE: The hd3 is the logical volume name used for the /tmp file system, and hd9var is the logical volume name used for /var. These names must be used if you wish to maintain your AIX system in an IBM supported state.
7. Create the file system with the following command:
crfs -v jfs -d hd9var -m /var -a check=false -a free=false -a vol=/var
NOTE: Substitute hd3 for hd9var and /tmp for /var if needed.
8. Mount the file system:
mount /var (OR mount /tmp)
9. If you are recreating /var, now create the /var/tmp directory for the vi editor. Execute:
mkdir /var/tmp
10. Set your TERM variable and export it.
11. Edit /etc/filesystems. If you have been recreating /tmp, invoke the vi editor by executing the following command:
vi -c "set dir=/" /etc/filesystems
If you have not been recreating /tmp, execute:
vi /etc/filesystems
Skip down to the stanza for either /var or /tmp. Within that stanza, go to the line that says mount = false and change the word false to automatic. Save the file and quit vi editor.
12. Change the ownership and permissions to the proper values, as follows:
chmod g-s /var
chmod 755 /var
chown bin.bin /var
or
chmod g-s /tmp
chmod 1777 /tmp
chown bin.bin /tmp
13. Restore the files from your backup. If you used the backup method given earlier in this document, execute:
cd /
tar -xvf /dev/rmt0
14. Remove the bootable media if you have not already done so.
15. If your system has a mode select key, switch it to the Normal position.
16. Reboot the system into Normal mode with the following:
sync;sync;sync;shutdown –Fr now

原文转自：http://www.ltesting.net