On Thu, Dec 08, 2016 at 07:54:39PM -0700, Chris Murphy wrote: > On Thu, Dec 8, 2016 at 7:26 PM, Darrick J. Wong <darrick.w...@oracle.com> > wrote: > > Ew, it's deduping these two 1.4GB files 128K at a time, which results in > > 12000 ioctl calls. Each of those 12000 calls has to lock the two > > inodes, read the file contents, remap the blocks, etc. instead of > > finding the maximal identical range and making a single call for the > > whole range. > > > > That's probably why it's taking forever to dedupe. > > Yes but it looks like it's also heavily fragmenting the files as a > result as well.
Thus I think it's better to do whole-file dedupe only, other than in some special cases (like VM images). Much simpler, faster and doesn't cause fragmentation. -- u-boot problems can be solved with the help of your old SCSI manuals, the parts that deal with goat termination. You need a black-handled knife, and an appropriate set of candles (number and color matters). Or was it a silver-handled knife? Crap, need to look that up. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
