* Yeb Havinga: > On 2011-07-19 12:47, Florian Weimer wrote: >> >>> It would be interesting to see if the drives also show total xyz >>> written, and if that differs a lot too. >> Do you know how to check that with smartctl? > smartctl -a /dev/<your disk> should show all values. If it shows > something that looks like garbage, it means that the database of > smartmontools doesn't have the correct information yet for these new > drives. I know that for the recently new OCZ vertex 2 and 3 SSDs you > need at least 5.40 or 5.41 and that's pretty new stuff. (I just > happened to install Fedora 15 today and that has smartmontools 5.41, > whereas e.g. Scientific Linux 6 has 5.39). Is this "Total_LBAs_Written"? The values appear to be far too low: 241 Total_LBAs_Written 0x0032 100 100 000 Old_age Always - 188276 242 Total_LBAs_Read 0x0032 100 100 000 Old_age Always - 116800 241 Total_LBAs_Written 0x0032 100 100 000 Old_age Always - 189677 242 Total_LBAs_Read 0x0032 100 100 000 Old_age Always - 92509 The second set of numbers are from the drive which wears more quickly. The read asymmetry is not unusual for RAID-1 configurations (depending on the implementation; few do "read both and compare", as originally envisioned, but prefer the primary block device instead). Reduced read traffic could translate to increased fragmentation and wear if the drive defragments on read. I don't know if the Intel 320s do this. -- Florian Weimer <fweimer@xxxxxx> BFK edv-consulting GmbH http://www.bfk.de/ Kriegsstraße 100 tel: +49-721-96201-1 D-76133 Karlsruhe fax: +49-721-96201-99 -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
