On Tue, 13 Dec 2011, Joshua Baker-LePain wrote:
On Wed, 14 Dec 2011 at 12:20pm, SINCOCK John wrote
Any advice on what might be going on here would be appreciated! - should
it really be necessary to delve into tuning vm system parameters just to
avoid memory fragmentation causing device drivers and system calls to
fail? To be messing around trying different vm paramaters just to make a
machine usable doesn't seem to make sense.
What I/O scheduler are you using? I've seen some suggest that when using a
(real) RAID card, the deadline scheduler is preferred over the default cfq.
Also, what FS are you using for your holding area? Finally, what is the
nature of the data you're backing up (i.e. does it involve *lots* of small
files)?
BTW, there was an interesting presentation at LinuxCon in Vancouver this past
summer by Christoph Hellwig on Filesystem/Storage tuning:
https://events.linuxfoundation.org/slides/2011/linuxcon/lcna2011_hellwig.pdf
In it he says the the default cfg I/O scheduler is a very bad default,
except on single-SATA spindle desktops - he recommends the deadline
scheduler.
cheers, etc.
--
deatrich @ triumf.ca, Science/Atlas PH: +1 604-222-7665
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