topic Re: No swap consum in Operating System - Linux

No swap consum

Carme Torca — Fri, 26 May 2006 01:47:21 GMT

Hi,

I have one system in linux, but it doesn't consums swap, and the processes doesn't works ok, because they don't have enough memory to work.

Mem: 3627456k av
Swap: 7550540k av

I have
JDK : 1.5.0_05
JBoss : 4.0.2

What could I do?
Could I do something to see that the system works ok?

Thanks a lot of!
Carmen.

Re: No swap consum

Stuart Browne — Fri, 26 May 2006 02:36:44 GMT

What does '/proc/meminfo' look like?

Is that 7GB of swap in one filesystem, or in multiple, smaller filesystems?

Re: No swap consum

Carme Torca — Fri, 26 May 2006 02:41:34 GMT

Here you are,

more '/proc/meminfo'
total: used: free: shared: buffers: cached:
Mem: 3714514944 1235329024 2479185920 0 192466944 517967872
Swap: 7731752960 0 7731752960
MemTotal: 3627456 kB
MemFree: 2421080 kB
MemShared: 0 kB
Buffers: 187956 kB
Cached: 505828 kB
SwapCached: 0 kB
Active: 717568 kB
ActiveAnon: 387636 kB
ActiveCache: 329932 kB
Inact_dirty: 339628 kB
Inact_laundry: 17196 kB
Inact_clean: 0 kB
Inact_target: 214876 kB
HighTotal: 2768832 kB
HighFree: 1874060 kB
LowTotal: 858624 kB
LowFree: 547020 kB
SwapTotal: 7550540 kB
SwapFree: 7550540 kB
HugePages_Total: 0
HugePages_Free: 0
Hugepagesize: 2048 kB

Thanks!

Re: No swap consum

Stuart Browne — Fri, 26 May 2006 02:52:56 GMT

MemTotal: 3627456 kB
MemFree: 2421080 kB

2GB of memory still isn't in use. Why cache when you have real memory ?!

Buffers: 187956 kB
Cached: 505828 kB

500MB as IO caching, with almost 200MB of disk buffers.

SwapTotal: 7550540 kB
SwapFree: 7550540 kB

As you say, none in use.

So, moral of the story: Application is only using approximately 512MB of memory at this point.

This means that either the application isn't memory intensive, or it's been tuned to only use a small memory footprint.

Look into your JBoss settings for your application.

Re: No swap consum

Carme Torca — Fri, 26 May 2006 04:20:44 GMT

ok, thank you.

Re: No swap consum

Bill Thorsteinson — Fri, 26 May 2006 17:11:41 GMT

If you need more memory for the Java process
change the -Xm options used to start the
java processes. Java has default values
if you don't specify them. For syntax help
run 'java -X'. Try adding something like
'-Xm512x' or -Xm1024x' to the java command
used to start jboss.

You may also need to investigate changing
the Java garbage collection options.
Default is to stop all activity while
garbage is collected.

Check the output of 'ulimit -a' to ensure you
don't have limits set there. These
can be changed in /etc/security/limits.conf.