ZFS

What is "Holding a ZFS Snapshot" feature Remote replication of ZFS datasets can result in different automatic snapshot policies on the two sides of a replication pair. For example, the sending side may want to keep five snapshots at one-minute intervals, whereas the receiving side may want to keep 10 snapshots at one-minute intervals. This can result in the older snapshots being destroyed inadvertently by zfs receive because they no longer exist on the sending side. The ZFS snapshot hold … [Read more...] about Understanding “Holding a ZFS Snapshot” Feature

To determine the differences between ZFS snapshots, you can use the zfs diff command. The output of this command provides a high-level description of the differences between a snapshot and a descendant dataset. The descendant can be either a snapshot of the data set or the current data set. For each file that has undergone a change between the original snapshot and the descendant, the type of change is described along with the name of the file. In the case of a rename, both the old and new names … [Read more...] about How to Identify ZFS Snapshot Differences using “zfs diff”

When a snapshot is created, its space is initially shared between the snapshot and the file system, and possibly with previous snapshots. As the file system changes, space that was previously shared becomes unique to the snapshot, and thus is counted in the snapshot’s used property. Additionally, deleting snapshots can increase the amount of space that is unique for use by other snapshots. Note: The value for a snapshot’s space referenced property is the same as that for the file system … [Read more...] about How to find the space consumed by ZFS snapshots

Creating and Destroying a ZFS Snapshot You can use the zfs snapshot command to create a snapshot, which takes as its only argument the name of the snapshot that you want to create. In the example below, you are creating a snapshot of datapool/home/user that is named friday. # zfs snapshot datapool/home/user@friday Note: To create a recursive snapshot, use zfs "snapshot -r" and the snapshot name (for example, zfs snapshot -r datapool/home@now). To destroy a ZFS snapshot, use the zfs … [Read more...] about Solaris ZFS : How to Create / Rename / Rollback / Destroy a ZFS Snapshot

What is a hot spare and how does it work? The ZFS hot spares feature enables you to identify disks that can be used to replace a failed or faulted device in one or more storage pools. Designating a device as a hot spare means that the device is not an active device in a pool, but if an active device in the pool fails, the hot spare automatically replaces the failed device. You can designate devices as hot spares with the zpool create command when you are creating a pool or with the zpool add … [Read more...] about Solaris ZFS : How to Designate Hot Spares in a Storage Pool