Thanks Greg We do not archive the WALs. We use application-level replication to achieve redundancy. WAL archiving was difficult to support with the earlier hardware we had ( 6x300G 10K disks Dell 2850) given the volumes we were dealing with. The RAID card should be from the same manufacturer (LSI in Dell's case). On our current system (6 x 450G 15K disks), we are able to sustain 100 million records/day but probably not more. On Wed, Apr 28, 2010 at 6:12 PM, Greg Smith <greg@xxxxxxxxxxxxxxx> wrote: > Anj Adu wrote: >> >> I am faced with a hardware choice for a postgres data warehouse >> (extremely high volume inserts..over 200 million records a day) > > That's an average of 2314 per second, which certainly isn't easy to pull > off. You suggested you're already running this app. Do you have any idea > how high the volume of data going to the WAL is relative to everything else? > >> 12 x 600G disks (15K) (the new Dell Poweredge C server) >> or >> 24 x 600G (10K disks) >> > > You can expect the 15K disks to be 30% (more sequential work) to 50% > (random/commit work) faster than a similar 10K drive. So from most > perspectives, twice as many 10K drives should be considerably faster. The > main point of concern here is the commit rate, which you can't necessarily > improve just by throwing drives at it. That's based on how fast the drives > spin, so there's the potential to discover a 50% regression there compared > to the setup you have right now. With the RAID card in there, it should be > fine, but it's something to be concerned about. > > Also, you didn't mentioned the RAID card for the new system, and whether it > would be the same in both setups or not. That can be as important as the > drives when you have larger arrays. The LSI Megaraid card Dell is using for > the Perc6i is quite fast, and you'll need to make sure you get something > just as good for the new server. > > -- > Greg Smith 2ndQuadrant US Baltimore, MD > PostgreSQL Training, Services and Support > greg@xxxxxxxxxxxxxxx www.2ndQuadrant.us > > -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
