I've seen posted here snippets of regularly running zfs send/recv and here's one below:
>So for example, each night you could do: ># zfs snapshot -r tank/[EMAIL PROTECTED] ># zfs send -R tank/[EMAIL PROTECTED] | ssh <otherhost> zfs recv -d backuptank ># zfs destroy -r tank/[EMAIL PROTECTED] ># zfs rename -r tank/[EMAIL PROTECTED] tank/[EMAIL PROTECTED] But when I tried this myself, I found out fairly quickly that it doesn't quite work. The very first go around this will appear to work, but on the first subsequent runs, it breaks down. In my examples, I'm using a pool called zfs-pool and zfs-pool/[EMAIL PROTECTED] for the most recently created source snapshot. First, the line zfs send -R zfs-pool/[EMAIL PROTECTED] | ssh targetssystem zfs recv -d zfs-pool complains with the error: cannot receive new filesystem stream: destination 'zfs-pool/home' exists must specify -F to overwrite it So then I tried zfs send -R zfs-pool/[EMAIL PROTECTED] | ssh targetssystem zfs recv -dF zfs-pool, and now it complains with the error: cannot receive new filesystem stream: destination has snapshots (eg. zfs-pool/[EMAIL PROTECTED]) must destroy them to overwrite it. But doing that causes the send/recv pair to write out the whole filesystem from scratch. I then learned about incrementally updating the prior source snapshot, which I have will have renamed to zfs-pool/[EMAIL PROTECTED] zfs send -R -i zfs-pool/[EMAIL PROTECTED] zfs-pool/[EMAIL PROTECTED] | ssh targetssystem zfs recv -d zfs-pool This command must be substituted for the command without the "-i" on that command's second and subsequent runs. However, each time it runs, it will create a cryptically named snapshot, such as @recv-3173-1, on the target system. What I learned is that this snapshot becomes the "current" snapshot of the target system and that trying to send another snapshot after deleting it outright results in the error: cannot receive incremental stream: destination zfs-pool/home has been modified since most recent snapshot. So to prevent a buildup of these snapshots, they can be renamed just as the current snapshot of the source system and then that renamed snapshot can be deleted after another snapshot from the source is sent over. Incidentally, the target system also gets copies of the two snapshots maintained on the source system. -- Maurice Volaski, [EMAIL PROTECTED] Computing Support, Rose F. Kennedy Center Albert Einstein College of Medicine of Yeshiva University _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
