allanjude
commented
8 years ago It depends on your before/after state.
In ZFS it is not possible to 'backfill' snapshots. You cannot transfer a snapshot that is older than the current snapshots on the destination. So on a second run, it can only work forward from where it was last time, it cannot go backwards.
When the do the very first replication, zxfer transfers the oldest snapshot, and then works forward from there.
You might need to check the 'grandfather' setting, since you do have some quite old snapshots.
So it seems it replicates all of the snapshots of the parent dataset, but then only some for the children? I have not seen this behaviour in my production use of zxfer.
This might be a bug, but more detail will need to be figured out to identify where the bug may be.
DarwinAwardWinner
SnapshotCiTy
I've been testing out zxfer as a way to backup the complete state of all filesystems, including all their snapshots, to an external hard drive. However, zxfer doesn't seem to be transferring old snapshots. It seems to have transferred all snapshots on the filesystem that I specified, but on the child filesystems I think it's only transferring snapshots that were made after the first time I ran zxfer. I am running zxfer as:
As it's running, it only mentions snapshots that were created/destroyed since the previous run, and doesn't mention the earlier snapshots at all. To count the snapshots on each filesystem, I use:
Counting the snapshots on the source (rpool/fs) and destination (backuppool/pools/fs):
As you can see, all snapshots for rpool/fs are backed up, but only about 15 snapshots from its child filesystems are backed up, despite the fact that they all have mant more. For example, I'll list only the snapshots for rpool/fs/home and its destination backuppool/pools/fs/home using the following function:
The destination copy only has filesystems created at 2:17 AM on 2016-07-16 or later, which I believe is all the snapshots made after the first time I ran the zxfer command mentioned above. Am I missing something about how to get zxfer to transfer old snapshots, or is this a bug?