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Chapter 1The following example shows softupdates enabled partitions:# mount/dev/ad0s1a on / (ufs, local)devfs on /dev (devfs, local)/dev/ad0s1e on /tmp (ufs, local, soft-updates)/dev/ad0s1f on /usr (ufs, local, soft-updates)/dev/ad0s1d on /var (ufs, local, soft-updates)In the above example, softupdates is enabled on /tmp, /usr, and /var partitions, butnot on the root partition. If you want to enable softupdates on the root partition, youmay use the tunefs(8) command as shown in the following example:# tunefs –n enable /Please note that you cannot enable or disable softupdates on an active partition (thatis currently mounted partition). To do so, you should first unmount the partitionor change it to read-only mode. In case you want to enable softupdates on rootpartition, it is recommended that you boot your system into single-user mode (inwhich your root partition is mounted as read-only) and then enable softupdatesusing the method mentioned in the above example.SnapshotsA file system snapshot is a frozen image of a live file system. Snapshots are veryuseful when backing up volatile data such as mail storage on a busy mail server.Snapshots are created under the file system that you are making snapshots from. Upto twenty snapshots can be created per file system.The mksnap_ffs(8) command is used to create a snapshot from FFS partitions:# mksnap_ffs /var /var/snap1Alternatively, you can use the mount(8) command to do the same:# mount –u –o snapshot /var/snap1 /varNow that you have created the snapshot, you can:• take a backup of your snapshot by burning it on a CD/DVD, or transfer it toanother server using ftp(1) or sftp(1).• Use dump(8) utility to create a file system dump from your snapshot.[ 13 ]