[Beowulf] LSI Megaraid stalls system on very high IO?
skylar.thompson at gmail.com
Tue Aug 5 20:49:01 PDT 2014
On 08/04/2014 01:24 AM, John Hearns wrote:
> Mark, you are of course correct.
> Flush often and flush early!
> As an aside, working with desktop systems with larger amounts of memory
> I would adjust the 'swappiness' tunable
> and also the min_free_kbytes.
> Min_free_kbytes in Linux is by default set very low for modern high
> memory systems.
> I had systems with 128Gbytes of RAM which would lock up in a similar
> fashion as you describe. Setting higher min_free_kbytes helped with the
> 'system paging itself into the deck' type of behaviour.
Agreed, and even more so when you have systems with hundreds of
gigabytes of RAM whose dirty buffers are backed by a single NFS server
with a fraction of that RAM for write cache.
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