On Fri, 12 Aug 2011, Ric Wheeler wrote: > On 08/12/2011 10:24 AM, Prof. Dr. Klaus Kusche wrote: > > On 2011-08-12 11:01, Ric Wheeler wrote: > > > Lukas has a more generic bulk tool that should do the job and has the > > > advantage that it does not have to fill the file system first (it can > > > lock regions and do its work). > > > > Any pointers to that? > > I think that the easiest (and most natural way) to do this is through the > updated fsck (-K) tool which will discard the unused block ranges when you > fsck a file system. > > Lukas can add in details about versions, etc :) Yes, you can use e2fsck to discard unused parst of the file system, hence reclaiming the space. This feature has been added with v1.41.12-162-gefa1a35 into e2fsprogs. Note that even though this operation should be safe, because we do discard at the end of the pass 5 and only if there was not any errors on the file system before, however this is relatively new feature and has not been extensively tested with corrupted images. Hmm, I really should write up this stuff into the web article somewhere :). Thanks! -Lukas > > > > > Thanks! > > > > > Note that discard is not just for physical devices like SCSI or ATA, it > > > is also useful for "software" stacks like various device mapper targets, > > > virtual block devices, etc so we should be keeping the abstraction at a > > > high level for our tooling. > > > > I agree, but wiper.sh has been the first such tool and is widespread > > and well-known. I'm not aware of alternatives using the generic fstrim > > command (which is still missing on some major distributions) > > or FITRIM ioctl. > > > > FITRIM is somewhat misnamed. It will end up issuing a discard to the storage > stack, not an ATA specific TRIM command (invoking sb_issue_discard()). > > Anything that uses FITRIM should work if I followed the code correctly, > > Ric > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
