On Sat, Mar 13, 2010 at 1:34 AM, A B <gentosaker@xxxxxxxxx> wrote: > Hello. > > It's time to get new hardware for a server that will run both > PostgreSQL and Apache. > The workload will be similar to that of your standard "PHP forum" > (most selects and logging of stuff that has been read) > > The modell I'm looking at right now is > > 2x Xeon E5520 2,26 GHz 8 MB (8 cores in total) > 24 GB 1066 MHz DDR 3 ECC (or more) > > When it comes to a RAID controller I have the choice of: > > 3Ware SAS 9690SA-8i 512 MB BBU > Adaptec SAS Raid 5805 256 MB BBU > LSI MegaRaid SAS 8708 128 MB BBU > > Any advice/experience on what raid controller to pick? The 3ware has > the most memory and I've read some good reviews on that one. > The OS will be CentOS 5.4 I can't comment on any of those particular controllers. There's a benchmark here: http://www.tomshardware.com/reviews/adaptec-serial-controllers,1806-11.html > When it comes to harddrives I think my best optins is to use > > * 4 discs (raid 10) for the database > > and > > * 4 discs (raid 10) for OS, xlog and other data (images,avatars etc.) > or more likely: > * 2 discs (raid 1) for OS/xlog and > * 2 discs (raid1) for "other data" Leaving out 2 drives for other data is kind of a waste of spindles. You can network mount terabytes from a file server full of SATA drives for much less. Also... > When it comes to choosing the acctual discs I guess this would be > appropriate to use: > "other data": Barracda ES.2 1000 GB (SATA) to get a a good GB/$ ratio. > OS/xlog : Barracuda ES.2 500 GB (SAS) > DB: Cheeta 15K.6 146 GB (SAS) (The 300 GB would be better if I can > find some more money) Mixing SATA and SAS drives on the same controller can be problematic. Some controllers don't behave well when you mix and match. I'd suggest building an 8 disk RAID-10 and a single mirror + 6 disk RAID-10 and testing both configurations. If you need more storage look at 300G SAS drives. Your two bottleneck are likely to be IO random write ops and / or CPU horsepower, depending on how your web app is built. You can always buy another $1500 box with hot cpus and a pair of big SATA drives if you need more CPU horsepower, but beefing up IO is a lot hard once your db server is in place. > This of course gives me a headache when it comes to keeping spare discs. > > The other option would be to use OS/xlog and DB on Barracuda ES.2 500 > GB (SAS). I have no idea what that mean to the performance. A lot/ > barely noticable? The cost diff now on 500 and 1TB drives is too low to bother with 500 and 1TB mixed, just get 1TB. And I can't really recommend Seagate ES.2 or 7200.11 drives right now with the failure rates I've been seeing. > Any comments, advice on this kind of setup? If you've got a lot of reads going on be sure to toss memcached into this equation. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
