Backing up a UFS snapshot incrementally means that only the files that have been modified since the last snapshot are backed up. Use the ufsdump command with the N option. This option specifies the file system device name to be inserted into the /etc/dumpdates file for tracking incremental dumps.
The following ufsdump command specifies an embedded fssnap command to create an incremental backup of a file system.
Become superuser or assume an equivalent role.
Create an incremental backup of a UFS snapshot.
# ufsdump 1ufN /dev/rmt/0 /dev/rdsk/c0t1d0s0 `fssnap -F ufs -o raw,bs= /export/scratch,unlink /dev/rdsk/c0t1d0s0`
In this example, the -o raw option is used to display the name of the raw device instead of the block device. By using this option, you make it easier to embed the fssnap command in commands (such as the ufsdump command) that require the raw device instead.
Verify that the snapshot has been backed up.
# ufsrestore ta /dev/rmt/0