On 09 August, 2010 - David Dyer-Bennet sent me these 1,2K bytes: > If I have a directory with a bazillion files in it (or, let's say, a > directory subtree full of raw camera images, about 15MB each, totalling > say 50GB) on a ZFS filesystem, and take daily snapshots of it (without > altering it), the snapshots use almost no extra space, I know. > > If I now rename that directory, and take another snapshot, what happens? > Do I get two copies of the unchanged data now, or does everything still > reference the same original data (file content)? Seems like the new > directory tree contains the "same old files", same inodes and so forth, so > it shouldn't be duplicating the data as I understand it; is that correct?
The files hasn't changed, unless you rename the directory by creating a new, copy stuff over and remove the old. The only change is the name of the directory. > This would, obviously, be fairly easy to test; and, if I removed the > snapshots afterward, wouldn't take space permanently (have to make sure > that the scheduler doesn't do one of my permanent snapshots during the > test). But I'm interested in the theoretical answer in any case. /Tomas -- Tomas Ögren, st...@acc.umu.se, http://www.acc.umu.se/~stric/ |- Student at Computing Science, University of Umeå `- Sysadmin at {cs,acc}.umu.se _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
