* Yeb Havinga: > On 2011-07-19 09:56, Florian Weimer wrote: >> * Yeb Havinga: >> >>> The biggest drawback of 2 SSD's with supercap in hardware raid 1, is >>> that if they are both new and of the same model/firmware, they'd >>> probably reach the end of their write cycles at the same time, thereby >>> failing simultaneously. >> I thought so too, but I've got two Intel 320s (I suppose, the report >> device model is "SSDSA2CT040G3") in a RAID 1 configuration, and after >> about a month of testing, one is down to 89 on the media wearout >> indicator, and the other is still at 96. Both devices are >> deteriorating, but one at a significantly faster rate. > That's great news if this turns out to be generally true. Is it on > mdadm software raid? Yes, it is. It's a mixed blessing because judging by the values, one of the drives wears down pretty quickly. > Maybe it is caused by the initial build of the array? But then a 7% > difference seems like an awful lot. Both drives a supposedly fresh from the factory, and they started with the wearout indicator at 100. The initial build should write just zeros, and I would expect the drive firmware to recognize that. I've got a second system against which I could run the same test. I wonder if it is reproducible. > 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? -- 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
