> I am unaware of *ANY* mainstream hard drive or SSD made in the > last 10 years which ignores the disk flush command. In previous > decades HD vendors played games with caching all the time but there > are fewer HD vendors now and they all compete heavily with each > other... they don't play those games any more for fear of losing > their reputation. There is very little vendor loyalty in the hard > drive business. > > When it comes to SSDs there are all sorts of fringe vendors, and I > certainly would not trust any of those, but if you stick to > well known vendors like Intel or OCZ it will work. Look for who's > chipsets are under the hood more than for whos name is slapped > onto the SSD and get as close to the source as you can.
As far as my knowledges goes all mainstream non-enterprise SSD do not obey the cache flush command at all. The question for a recommended SSD for ZIL-use regularly comes up on the zfs-discuss mailing list and the general consensus seems that no non-enterprise SSD can really be recommended because of this issue. The only publicly available SSDs which do not exhibit this are those with a Sandforce enterprise controller (SF-1500 if my memory serves me correctly) and a capacitor (OCZ sells such models) and the Intel X25-E with it's write cache turned off (also resulting in horrible write performance all around). I've had the chance to verify this with a Corsair Force SSD with the SF-1200 controller. It consistently "lost" about 1,2 to 1,5 MB of data which it claimed to have committed to disk. Regards Florian
signature.asc
Description: PGP signature
