Sadly this is for a customer who has 3000 of these in the field, the raid controller is on the motherboard.
At least they know where to point the finger now!
Cheers,
James Sewell,
PostgreSQL Team Lead / Solutions Architect
Suite 112, Jones Bay Wharf, 26-32 Pirrama Road, Pyrmont NSW 2009
On Fri, Feb 17, 2017 at 1:25 AM, Merlin Moncure <mmoncure@xxxxxxxxx> wrote:
On Tue, Feb 14, 2017 at 7:23 PM, James Sewell <james.sewell@xxxxxxxxxxxx> wrote:OK,So with some help from the IRC channel (thanks macdice and JanniCash) it's come to light that my RAID1 comprised of 2 * 7200RPM disks is reporting ~500 ops/sec in pg_test_fsync.This is higher than the ~120 ops/sec which you would expect from 720RPM disks - therefore something is lying.Breaking up the RAID and re-imaging with JBOD dropped this to 50 ops/sec - another question but still looking like a real result.So in this case it looks like the RAID controller wasn't disabling caching as advertised.yup -- that's the thing. Performance numbers really tell the whole (or at least most-) of the story. If it's too good to be true, it is. These days, honestly I'd just throw out the raid controller and install some intel ssd drives.merlin
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