On 2011-11-21, Christiaan Willemsen <cwillemsen@xxxxxxxxxxxxx> wrote: >We= > are looking at beefing up our servers with SSD's. Some of you did so= > me interesting tests with the Intel 320. So the idea came to make a RAID1= > 0 with four 600GB models.</p><p> </p><p>I did however do some calcul= > ations with the current database server (220GB database, expected to grow= > to 1TB by the end of next year). I specifically looked at /proc/diskstat= > at the read/write figures. From there I could see a read/write ratio of = > 3:1, and I also saw a wopping 170GB of writes per day (for a database tha= > t currently grows 1GB per dag). That seems like an insanely high figure t= > o me! How come=3F We do mostly inserts, hardly any updates, virtually no = > deletes.</p><p> </p><p>Secondly, I also looked at the reliability fi= > gures of the Intel 320. They show 5 years of 20GB per day, meaning that i= > t will hold up for about 200 days in our system. RAID 10 wil make 400 day= > s of that, but this seems hardly a lot.. Am I missing something here=3F</= > p><p> </p><p>Kind regards,</p><p> </p><p>Christiaan</p><div><p = > style=3D"font-family: monospace; "> </p></div><p> </p><p> = ></p>=0A</body>=0A</html> Is your WAL on a separate disk (or set of disks)? Also, not sure you can fairly conclude that "RAID 10 will make 400 days of that" -- I had read some posts here a few months back suggesting that SSDs have been observed to fail very close to each other in time in a RAID configuration. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
