On Tue, 28 Jun 2011, Mathias Burén wrote:
IIRC md can already pass TRIM down, but I think the filesystem needs to know about the underlying architecture, or something, for TRIM to work in RAID.
Yes, it's (usually/ideally) the filesystem's job to invoke the TRIM command, and that's what ext4 can do. I have it working just fine on single drives, but for reasons of service reliability would need to get RAID to work.
I tried (on an admittedly vanilla Ubuntu 2.6.38 kernel) the same on a two drive RAID1 md and it definitely didn't work (the blocks didn't get marked as unused and zeroed).
There's numerous discussions on this in the archives of this mailing list.
Given how fast things move in the world of SSDs at the moment, I wanted to check if any progress was made since. :-) I don't seem to be able to find any reference to this in recent kernel source commits (but I'm a complete amateur when it comes to git).
Thanks, -- Tom De Mulder <tdm27@xxxxxxxxx> - Cambridge University Computing Service +44 1223 3 31843 - New Museums Site, Pembroke Street, Cambridge CB2 3QH -> 29/06/2011 : The Moon is Waning Crescent (18% of Full)
