A Snapshot file system is an exact image of a VxFS file system, referred to as the snapped file system, that provide a mechanism for making backups. The snapshot is a consistent view of the file system "snapped" at the point in time the snapshot is made. We can select files to back up from the snapshot using a standard utility such as cpio or cp, or back up the entire file system using the vxdump or fscat utilities.
We use the mount command to create a snpshot file system; th mkfs command is not required. A snapshot file system is always read-only. A snapshot file system exists only as long as it and the snapped file system are mounted and cease to exist when unmounted. A snapped file system cannot be unmounted until all of its snapshots are unmounted. Although it si possible to have multiple snapshot of a file system made at different times, it is not possible to make a snapshot of a snapshot.
On cluster file system, snapshots can be created on any node in the cluster, and backup operations can be performed from that node. The snapshot of a cluster file system is accessible only on the node whre it is created, that is, the snapshot file system itself cannot be cluster mounted.
We use the mount command to create a snpshot file system; th mkfs command is not required. A snapshot file system is always read-only. A snapshot file system exists only as long as it and the snapped file system are mounted and cease to exist when unmounted. A snapped file system cannot be unmounted until all of its snapshots are unmounted. Although it si possible to have multiple snapshot of a file system made at different times, it is not possible to make a snapshot of a snapshot.
On cluster file system, snapshots can be created on any node in the cluster, and backup operations can be performed from that node. The snapshot of a cluster file system is accessible only on the node whre it is created, that is, the snapshot file system itself cannot be cluster mounted.