Heap storage and virtual memory

[Richard Bassemir]

I am running an application on a N4000 that has 8 gigs of memory. The application is failing and the documentation I have on the failure says the most likely the heap storage has been exhausted and to check the system's virtual memory.

I am rather green with HP Unix, can anyone tell me how I might check virtual storage usage. I have run swapinfo -ta that appears to be normal but I don't know if I am looking in the right place for an solution.

[James R. Ferguson · Accepted solution]

Richard:

It sounds like either additional swap space needs configuration or the kernel's 'maxdsiz' should be increased. Check for swap utilization with:

# swapinfo -ta

For more information on 'maxdsiz' see:

http://docs.hp.com/hpux/onlinedocs/os/KCparams.OverviewAll.html

What is the specific error message your application returns?

...JRF...

[Richard Bassemir]

John, here was the actual command I ran although it might not mean too much to you it is an InterMail Mx command.

hp1:imail5_1_2% ./lib/imdirmake -r imdircacheserv
imdirmake: Notice: found existing database, version "".
>>> Proceed to recreate database [y/n]? y
imdirmake: recreating database...
imdirmake: Fatal -- SysNoSpace(71/3) 0:1138491393:67108864:67108864:0:0
IOT trap
hp1:imail5_1_2%

We observed the following line a number of times in the syslog.log

"...vmunix: file: table is full"

Could this be some indication that virtual memory is used up??

[James R. Ferguson]

Richard:

"File table full" means that the Kernel 'nfile' parameter ceiling has been reached. 'nfile' defines the maximum number files that can be open at any one time, system-wide (see the Kernel overview document in my earlier post, above). Be sure to read about 'maxfiles' and 'maxfiles_lim' too.

With 'nfile' I prefer to increase 'maxusers' as this has the "most" influence on the 'nfile' value when using the standard formula for 'nfile' computation (see the document and/or SAM).

In general, it's best to stick with the formulas provided for configuring parameters. In this way, interrelated parameters are adjusted in a balanced way.

SAM's interface to kernel tuning has excellent inbuilt help. In addition, SAM enforces the limits (minimum and maximum) of the various parameters, making it difficult to make mistakes.

To change any of these kernel parameters will require a reboot, so plan accordingly.

BTW, 'sar -v' will report your file table size, as will the 't'able reporting in the Glance performance monitor (if you have that).

...JRF...