backing up zfs dataset

[Johannes Totz]

Hi,

To back up a zfs dataset there are a few possibilities:
1) rsync file data to another machine
2) zfs-send to another machine, into a zfs dataset
3) zfs-send to another machine, dumping the stream to a file

The first one works alright but you loose admin info, properties set on 
the dataset, etc
The second is prefered but requires another machine which runs zfs.
The third is bad.

So far I have been doing (3), for daily short-term backups, works, 
tested, everything is peachy. However, I dont like it anymore for 
obvious reasons. Ideally, I would like to go with (2). But I dont have 
another zfs-capable machine, or the machine that I would like to backup 
onto will not ever run zfs.

So I came up with another crazy idea, assuming the remote machine 
exports a block device (somehow):
4) zpool-attach the remote block dev as a mirror, let it resilver, 
offline it during the day, at night online it, resilver, and so on
5) create a pool on the block dev locally on the to-be-backed-up-machine 
and periodically zfs-send stuff over

I would go for (4), it seems to be the mostly automatic.
Any thoughts on this?
Should I expect things to go titsup if there's network issues?



Johannes