| From: | Greg Smith <greg(at)2ndquadrant(dot)com> |
|---|---|
| To: | Merlin Moncure <mmoncure(at)gmail(dot)com> |
| Cc: | Brad Nicholson <bnichols(at)ca(dot)afilias(dot)info>, Karl Denninger <karl(at)denninger(dot)net>, Laszlo Nagy <gandalf(at)shopzeus(dot)com>, pgsql-performance <pgsql-performance(at)postgresql(dot)org> |
| Subject: | Re: SSD + RAID |
| Date: | 2009-11-17 18:51:13 |
| Message-ID: | 4B02F0A1.9060304@2ndquadrant.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-performance |
Merlin Moncure wrote:
> I am right now talking to someone on postgresql irc who is measuring
> 15k iops from x25-e and no data loss following power plug test.
The funny thing about Murphy is that he doesn't visit when things are
quiet. It's quite possible the window for data loss on the drive is
very small. Maybe you only see it one out of 10 pulls with a very
aggressive database-oriented write test. Whatever the odd conditions
are, you can be sure you'll see them when there's a bad outage in actual
production though.
A good test program that is a bit better at introducing and detecting
the write cache issue is described at
http://brad.livejournal.com/2116715.html
--
Greg Smith 2ndQuadrant Baltimore, MD
PostgreSQL Training, Services and Support
greg(at)2ndQuadrant(dot)com www.2ndQuadrant.com
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Merlin Moncure | 2009-11-17 19:19:35 | Re: SSD + RAID |
| Previous Message | Peter Eisentraut | 2009-11-17 17:30:13 | Re: SSD + RAID |