Musings on ZFS Backup strategies

[David Magda]

On Mar 1, 2013, at 12:55, Volodymyr Kostyrko wrote:

> Yes, I'm working with backups the same way, I wrote a simple script that synchronizes two filesystems between distant servers. I also use the same script to synchronize bushy filesystems (with hundred thousands of files) where rsync produces a too big load for synchronizing.
> 
> https://github.com/kworr/zfSnap/commit/08d8b499dbc2527a652cddbc601c7ee8c0c23301

There are quite a few scripts out there:

	http://www.freshports.org/search.php?query=zfs

For file level copying, where you don't want to walk the entire tree, here is the "zfs diff" command:

> zfs diff [-FHt] snapshot [snapshot|filesystem]
> 
> 	 Describes differences between a snapshot and a successor dataset. The
> 	 successor dataset can be a later snapshot or the current filesystem.
> 
> 	 The changed files are displayed including the change type. The change
> 	 type is displayed useing a single character. If a file or directory
> 	 was renamed, the old and the new names are displayed.

http://www.freebsd.org/cgi/man.cgi?query=zfs

This allows one to get a quick list of files and directories, then use tar/rsync/cp/etc. to do the actual copy (where the destination does not have to be ZFS: e.g., NFS, ext4, Lustre, HDFS, etc.).