Re: PostgreSQL corruption

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
*P *(+61) 2 8099 9000 <(+61)%202%208099%209000> *W* www.jirotech.com *F *
(+61) 2 8099 9099 <(+61)%202%208099%209000>

On Fri, Feb 17, 2017 at 1:25 AM, Merlin Moncure <mmoncure(at)gmail(dot)com> wrote:

> On Tue, Feb 14, 2017 at 7:23 PM, James Sewell <james(dot)sewell(at)jirotech(dot)com>
> 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
>

--

------------------------------
The contents of this email are confidential and may be subject to legal or
professional privilege and copyright. No representation is made that this
email is free of viruses or other defects. If you have received this
communication in error, you may not copy or distribute any part of it or
otherwise disclose its contents to anyone. Please advise the sender of your
incorrect receipt of this correspondence.