On 09/10/12 11:48, Craig James wrote:
On Mon, Oct 8, 2012 at 3:44 PM, Claudio Freire <klaussfre...@gmail.com>wrote:
On Mon, Oct 8, 2012 at 7:25 PM, Craig James <cja...@emolecules.com> wrote:
But why? What have I overlooked?
Do you have readahead properly set up on the new one?
# blockdev --getra /dev/sdb1
256
It's probably this. 256 is way too low to saturate your I/O system.
Pump it up. I've found 8192 works nice for a system I have, 32000 I
guess could work too.
But again ... the two systems are identical. This can't explain it.
Maybe check all sysctl's are the same - in particular:
vm.zone_reclaim_mode
has a tendency to set itself to 1 on newer hardware, which will reduce
performance of database style workloads.
Cheers
Mark
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