On Fri, 2009-04-03 at 12:43 +0100, Ric Wheeler wrote: > > New firmware/microcode versions are able to reclaim that space if it > > sees a certain number of consecutive zero's and will reclaim that > > space to the volume pool. Are there any thoughts on writing a > > low-priority tread that zeros out those "non-used" blocks? > > Patches have been floating around to support this - see the recent > patches around "DISCARD" on linux-ide and lkml. It would be great to > get access to a box that implemented the T10 proposed UNMAP commands > that we could test against. We've already made btrfs support TRIM, and Matthew has patches which hook it up for ATA/IDE devices. Adding SCSI support shouldn't be hard once the dust settles on the spec. I don't think I've seen anybody talking about deliberately writing zeroes instead of just issuing a discard command though. That doesn't seem like a massively cunning plan. -- David Woodhouse Open Source Technology Centre David.Woodhouse@xxxxxxxxx Intel Corporation -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
