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 <user-70507ff7198d@xymon.invalid> 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.
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Providence, RI XXXXX
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