Swap issues with Linux 2.4.20-xx - Caching is causing unnecessary swaping
jim at wangtrading.com
Fri Jan 30 15:01:01 CST 2004
Excellent information! I'm pulling the patch down now.
I have been tweaking and tesing /proc settings, plus reading kernel code all
From: Wolfgang Baudler [mailto:wbaudler at gb.nrao.edu]
Sent: Friday, January 30, 2004 3:58 PM
To: jim at wangtrading.com; linux-poweredge at dell.com
Subject: Re: Swap issues with Linux 2.4.20-xx - Caching is causing
Jim Laverty wrote:
> This is not a Dell specific question/issue, however the results are
> to the hanging issues being brought up. So far everyone I have spoken to
> has not noticed this, until we mentioned it and asked them to check
> their servers. Has anyone run into this issue below and found a
> reasonable way to fix it, without disabling swap?
> Since we have switched from the 2.4.18-xx kernels to the 2.4.20-xx
> kernels, we have noticed that servers which do a lot of NFS traffic
> are chewing up the cache and causing the system to swap even though
> the apps are not using that much memory. What happens is that the
> system starts to swap and eventually comes to a crawl, since the
> 'cached' data never seems to get freed. This may not be limited to
> NFS only, however that is where most of the testing has been done.
We had similar problems on all our machines that have more then 1GB of
memory. Any of the Redhat 2.4.20 or stock 2.4.20 kernels should this
The solution is to either disable the extra memory (mem=1024M boot option)
to compile a kernel with the aa1 patches installed. 2.4.23aa1 works fine in
The patch is available for example at
This patch also applied clean against the 2.4.24 kernel.
( happily running a DELL PE 8450 with 8GB of RAM now...)
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