Identifying ZFS Snapshot Differences (zfs diff)

You can determine ZFS snapshot differences by using the zfs diff command.

For example, assume that the following two snapshots are created:

$ ls /tank/home/tim
fileA
$ zfs snapshot tank/home/tim@snap1
$ ls /tank/home/tim
fileA  fileB
$ zfs snapshot tank/home/tim@snap2

For example, to identify the differences between two snapshots, use syntax similar to the following:

$ zfs diff tank/home/tim@snap1 tank/home/tim@snap2
M       /tank/home/tim/
+       /tank/home/tim/fileB

In the output, the M indicates that the directory has been modified. The + indicates that fileB exists in the later snapshot.

The R in the following output indicates that a file in a snapshot has been renamed.

$ mv /tank/cindy/fileB /tank/cindy/fileC
$ zfs snapshot tank/cindy@snap2
$ zfs diff tank/cindy@snap1 tank/cindy@snap2
M       /tank/cindy/
R       /tank/cindy/fileB -> /tank/cindy/fileC

The following table summarizes the file or directory changes that are identified by the zfs diff command.

File or Directory Change Identifier File or directory has been modified or file or directory link has changed M File or directory is present in the older snapshot but not in the more recent snapshot — File or directory is present in the more recent snapshot but not in the older snapshot + File or directory has been renamed R

For more information, see zfs(1M).