Thanks both of you for your input. Earlier I have been discussing my extremely high IO wait with you here on the mailing list, and have tried a lot of tweaks both on postgresql config, wal directly location and kernel tweaks, but unfortunately my problem persists, and I think I'm eventually down to just bad hardware (currently two 7200rpm disks in a software raid 1). So changing to 4 15000rpm SAS disks in a raid 10 is probably going to change a lot - don't you think? However, we are running a lot of background processing 300 connections to db sometimes. So my question is, should I also get something like pgpool2 setup at the same time? Is it, from your experience, likely to increase my throughput a lot more, if I had a connection pool of eg. 20 connections, instead of 300 concurrent ones directly?
Den 01/03/2013 kl. 16.28 skrev Craig James <cja...@emolecules.com>: > On Fri, Mar 1, 2013 at 3:43 AM, Niels Kristian Schjødt > <nielskrist...@autouncle.com> 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-r720 with four > SAS drives in a RAID 10 array. Has any of you any particular > comments/pitfalls/etc. to mention on the setup? My application is very write > heavy. > > I can only tell you our experience with Dell from several years ago. We > bought two Dell servers similar (somewhat larger) than the model you're > looking at. We'll never buy from them again. > > Advantages: They work. They haven't failed. > > Disadvantages: > > Performance sucks. Dell costs far more than "white box" servers we buy from > a "white box" supplier (ASA Computers). ASA gives us roughly double the > performance for the same price. We can buy exactly what we want from ASA. > > Dell did a disk-drive "lock in." The RAID controller won't spin up a > non-Dell disk. They wanted roughly four times the price for their disks > compared to buying the exact same disks on Amazon. If a disk went out today, > it would probably cost even more because that model is obsolete (luckily, we > bought a couple spares). I think they abandoned this policy because it > caused so many complaints, but you should check before you buy. This was an > incredibly stupid RAID controller design. > > Dell tech support doesn't know what they're talking about when it comes to > RAID controllers and serious server support. You're better off with a > white-box solution, where you can buy the exact parts recommended in this > group and get technical advice from people who know what they're talking > about. Dell basically doesn't understand Postgres. > > They boast excellent on-site service, but for the price of their computers > and their service contract, you can buy two servers from a white-box vendor. > Our white-box servers have been just as reliable as the Dell servers -- no > failures. > > I'm sure someone in Europe can recommend a good vendor for you. > > Craig James > > > > > -- > Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance >
