UNIX for Dummies Questions & Answers

Good question! We are concerned that if we try to reboot the system it will hang due to the /tmp being full. Is that a valid concern?'

Steve

I don't use AIX, but I can't imagine why it would. I would reboot.

this could be one of the possible case...

check whether any of ur process is using IPC's like shared memory, mesage queues etc

and check out where these segement ID's are given in .

If so in swap space /tmp that could be a problem

This is just one possible reason.

In solaris, I will do a prstat -avm, in linus, I will do a top, in AIX, i dunno.
I will look for the largest resident size (memory used).

E.g. Try sending out a large mail from unix, you will see the /tmp is used when the physical memory is used up. The resident memory will increase steadily at the same time under the sendmail process.
Kill the sendmail process, /tmp will be back to 0%.

In AIX you could use "topas", which is from the package bos.perf.tools.

Issue "lslpp -l bos.perf.tools" to see which version of this fileset is installed if any and invoke it with "topas".

Alternatively you could use "nmon", which is similar to topas, but not officially supported by IBM. Another alternative would be "monitor", which is also not officially supported, but can be downloaded from the Bull-site. Invoke it with "monitor -top". At least one of these tools should be installed on every system. If it isn't - hang your SysAdmin to the next lantern pole for proven indolence.

I can assure you the machine *will* survive a reboot even with a full /tmp filesystem, there will be no problems because of this.

The .map-files are presumably ASCII files containing the layout of the logical volumes (more or less: filesystems) on the disks. Delete them, you can easily create them anew with "lslv -Lm <LVname> [> <file>]".

If you have to increase the size of the /tmp-filesystem:

Issue "lsvg rootvg" to get the PP size (in the right column near the top). You can increase the size in multitudes of this unit. Lets say it is 32MB. If you want to add 128 MB to the filesystem you will have to add 4 such partitions (4x32=128). Don't care about mirroring or so, this is handled by the logical volume manager automatically. Per default /tmp is on the LV hd3. Issue

Code:

# extendlv hd3 4

This will increase LV hd3 by adding 4 logical partitions (if the LV is mirrored this would add 8 partitions physically on different disks, yielding 4 partitions logically, or even 12 PPs on 3 disks if there are two copies).

Now that you have increased the LV you need to increase the FS to make use of the additional room. This time you have to specify the space in blocks, which are 512 Bytes big. First we calculate how many blocks the 128 MB are:

Code:

# print - "4*32*1024*2" | bc
262144

The result is used to increase the filesystem:

Code:

# chfs -a size=+262144 /tmp

The filesystem is now increased by 128 MB. Don't bother to umount the FS, this is not necessary. You can do all that while the applications are running without any problem.

Hope this helps.

bakunin