On Thu, 2013-02-21 at 16:46 +0100, Swâmi Petaramesh wrote: > Hi again, > > Having numerous snapshots, I prefer to ask rather than take the risk of > exploding my storage space, better safe than sorry ;-) > > "man btrfs" states : > > « NOTE: defragmenting with kernels up to 2.6.37 will unlink COW-ed > copies of data, don't use it if you use snapshots, have > deduplicated your data or made copies with cp --reflink. » > > I use : > # uname -r > 3.5.0-24-generic > > ...So should I expect that defraging my BTRFS will be smart enough not > to uncow my snapshots ? Is it actually able to defrag both the file and > its snapshots altogether, keeping all this as a single physical copy of > the defragged data ?
The message in the btrfs man page is a bit out of date - defragmenting files on btrfs will uncow files on all currently released kernels. There's a patch available to fix this, but it hasn't been merged yet. It might show up in 3.9 or 3.10. You really should upgrade your kernel, however. 3.5.0 is rather old in btrfs-years! Lots of fixes have gone into newer kernels. -- Calvin Walton <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
