Also it is worth checking what your sysctl vm.zone_reclaim_mode is set
to - if 1 then override to 0. As Jeff mentioned, this gotcha for larger
cpu number machines has been discussed at length on this list - but
still traps us now and again!
Cheers
Mark
On 02/04/13 19:33, Armand du Plessis wrote:
I had my reservations about my almost 0% IO usage on the raid0 array as
well. I'm looking at the numbers in atop and it doesn't seem to reflect
the aggregate of the volumes as one would expect. I'm just happy I am
seeing numbers on the volumes, they're not too bad.
One thing I was wondering, as a last possible IO resort. Provisioned EBS
volumes requires that you maintain a wait queue of 1 for every 200
provisioned IOPS to get reliable IO. My wait queue hovers between 0-1
and with the 1000 IOPS it should be 5. Even thought about artificially
pushing more IO to the volumes but I think Jeff's right, there's some
internal kernel voodoo at play here. I have a feeling it'll be under
control with pg_pool (if I can just get the friggen setup there right)
and then I'll have more time to dig into it deeper.
Apologies to the kittens for the interrupting your leave :)
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