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VenkatabhargavFlag for India

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How to change /tmp path to a different mount point on AIX 5L

We are using AIX 5L Server (64 Bit) version 5300-05 series. And we have a setup of Oracle Applications on this server. As this is our reports server, Oracle writes many temporary files to this /tmp folder on hdisk0.

When i do topas, i could see that the disk utilization is 100% for most of the times. and this folder is filled and emptied continuously by Oracle. We have also encountered Page outs.

Memory utilization is always less than or equal to 80% and paging utilization is 19%, but during peak time the memory is never utilized fully but paging swap file is utilized fully.


We have 19 GB ram and 8 Processors on dual core and daily we have over 500 users logging concurrently and firing all heavy reports.

Please help me on configuring my server optimally so that i can run my application server peacefully.
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sanjooz

Here is one way :

mount your new partition or folder or whatever. Say it is on /newtmp.

rename your /tmp to /tmp.old
create a symbolic link ln -s /newtmp /tmp
rm -rf /tmp.old

You wrote that during peak time the memory is never utilized fully but that there is paging activity. You could try to set the lru_file_repage vmo option to 0. If set to 0, the algorithm will strongly prefer stealing file pages to satisfy memory requests.
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sjm_ee
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Do you have another (faster) type of device that you can mount /tmp on?

If so, the best way to do this is to use "smit fs" then select "Change Filesystem -> Journaled File System (or Enhanced JFS if your current /tmp file system is jfs2). then select Change Characteristics of File System. Select /tmp, and change the mount point to something like /tmp2.

Now create a new /tmp filesystem on your other device by again using "smit fs" then Add Filesystem. You'll probably want to use Enhanced Journaled File System if your in 64 bit more on a newer version of AIX.
Select the volume group and create a new filesytem, it will also create a new logical volume in the process.

If you don't have a faster disk setup you may want to look into using a RAM file system. This is much faster than disk access, but it is volatile. You will lose everything across a reboot.... but thats ok for /tmp because you shouldn't be storing anything important there.

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Hi all,

There is one kernel parameter called as MAXPARAM which had a default value of 50,.. and now it has been reduced to 15.. this has for the time being reduced the swap file utilization, secondly certain kernel parameters were changed which gave unlimited access to use the resources.


But the sysadmin team here is strictly against the idea of moving the /tmp to other mount point...:(( any other way to tune up..?
You can use 'smitty' to grow /tmp filesystem without interrupting the filesystem.
/tmp is one of standard filesystems best if it resides on boot controller. No need to relocate that far away.
thats the problem... the /tmp is residing on boot controller.. thats why the sysadmin team is not budging on moving it to a different location.. but my system generates almost 5 to 6 mb tmp file per report of heavy report engines...

in a fix.. it seems either i have to move the reports server to a diff server and adhere extra cost or schedule my reports at night or at times when the user load is very low....

You need to get into another directory. sysadmin will be happy to help you with one. Make sure your crapplication server cleans up after itself.