On Oct 28, 2014 12:38 AM, "Rich Freeman" <ri...@gentoo.org> wrote: > > On Mon, Oct 27, 2014 at 1:23 PM, Volker Armin Hemmann > <volkerar...@googlemail.com> wrote: > > Am 27.10.2014 um 16:36 schrieb Rich Freeman: > >> and a boot > >> partition as I don't think grub supports it - it could be a bit of a > >> PITA for a single-drive system. > > > > nope. But I don't see any reason to use zfs with a single drive either. > > True, not needing to use FUSE does simplify things, but I don't > believe that grub supports zfs, so you would need a boot partition. > Granted, a newer laptop would need that for EFI anyway. > > > > >> However, it is probably more mature > >> than btrfs overall, and it certainly supports send. > > > > and if your send stream is corrupted, your data is gone. That is why I > > prefer cp&tar to backup my zfs data tank. > > > > If you ONLY save the send stream without checking it, then you're > right that you're depending on its integrity. I'd certainly be > nervous about doing that with btrfs, probably less so with zfs but I > can't really vouch for it. I don't know what ability either > filesystem gives you to verify a send stream in isolation. > > Now, what you could do is receive the send stream into a replica > filesystem on the far end, and not consider the backup successful > until this is done. That would look like a btrfs-to-btrfs rsync > operation, but it would be much more efficient in terms of IO. It > would require a daemon on the far end to run the receive operation and > report back status, vs just dumping the files via scp, etc. > > Does anybody know if either btrfs or zfs send includes checksums? I > know the data is checksummed on disk, but I have no idea if it is > protected in this way while serialized. >
zfs has checksum for the send stream. That's why you can send the stream to a file, and fail to import the file sometime later if something changes in that file. So, always do a filesystem replication. Don't just save the send stream. Have the replica make the snapshots visible in poolroot/.zfs, and backup the whole filesystem using a deduping backup system. Rgds, --
