Re: [hobbit] Memory check

[Ralph Mitchell <ralphmitchell (at) gmail.com>]

I'm not sure on the details, but I believe the Linux kernel loads up a
large percentage of available memory with disk buffers as files are
read.  Those buffers don't really count against any process and will
be evicted as soon as an actual process asks for real memory.  The
idea is that it speeds up disk access for those files that are in
memory, and doesn't cost much (in machine time) to keep them around
until the space is needed for something else.

Memory usage spikes during a backup because it's reading *all* the
files on disk...

Ralph Mitchell


On 2/7/06, David Gilmore <david (at) stenhouseconsulting.com> wrote:
>
> My hobbit server (Fedora FC4) has 1.25 gig of memory installed.  When the
> server is backed, up using Retrospect client, REAL memory usage spikes from
> 34% to 97% and stays at that level until a reboot.  When I check the system
> performance, using the built in system monitor, user memory is at 18.9%.
> Dell Open Manage is using the most memory at 3% with a few additional
> processes between 1% and 2%.  Everything else is well under 1%.  What
> exactly is hobbit reporting on when it says that Physical/Real memory is at
> 97%, Actual memory is at 17%, and Swap is at 0%?
>
> Thanks,
>
> David Gilmore
> Consultant
> Stenhouse Consulting, LLC.
> 4 Traverse St
> Providence, RI   02906
> 401.453.6900
> 401.454.7581 (fax)