On 3/1/13 6:43 AM, Niels Kristian Schjødt wrote:
> Hi, I'm going to setup a new server for my postgresql database, and I am considering one of these:
http://www.hetzner.de/hosting/produkte_rootserver/poweredge-r720with four SAS drives in a RAID 10 array. Has any of you
anyparticular comments/pitfalls/etc. to mention on the setup? My application is very write heavy.
The Dell PERC H710 (actually a LSI controller) works fine for
write-heavy workloads on a RAID 10, as long as you order it with a
battery backup unit module. Someone must install the controller
management utility and do three things however:
1) Make sure the battery-backup unit is working.
2) Configure the controller so that the *disk* write cache is off.
3) Set the controller cache to "write-back when battery is available".
That will use the cache when it is safe to do so, and if not it will
bypass it. That will make the server slow down if the battery fails,
but it won't ever become unsafe at writing.
See http://wiki.postgresql.org/wiki/Reliable_Writes for more information
about this topic. If you'd like some consulting help with making sure
the server is working safely and as fast as it should be, 2ndQuadrant
does offer a hardware benchmarking service to do that sort of thing:
http://www.2ndquadrant.com/en/hardware-benchmarking/ I think we're even
generating those reports in German now.
--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com
