[Beowulf] LSI Megaraid stalls system on very high IO?

[mathog]

On 31-Jul-2014 10:36, Joe Landman wrote:
> On 7/31/14, 12:37 PM, mathog wrote:
>> Any pointers on why a system might appear to "stall" on very high IO 
>> through an LSI megaraid adapter?  (dm_raid45, on RHEL 5.10.)
> What IO scheduler are you using?
> 
>     cat /sys/block/sd*/queue/scheduler

% cat /sys/block/sd*/queue/scheduler
noop anticipatory deadline [cfq]
noop anticipatory deadline [cfq]
noop anticipatory deadline [cfq]

Thanks,

David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech