RAID-1 Volumes (Mirrors)

A RAID-1 volume, or mirror, is a volume that maintains identical copies of the data in RAID-0 volumes (single-slice concatenations.) Mirroring requires an investment in disks. You need at least twice as much disk space as the amount of data you have to mirror. Because Solaris Volume Manager software must write to all submirrors, mirroring can also increase the time that is required for write requests to be written to disk.

With RAID-1 volumes, data can be read from both RAID-0 volumes simultaneously (either volume can service any request), providing improved performance. If one physical disk fails, you can continue to use the mirror with no loss in performance or loss of data.

After you configure a mirror, the mirror can be used just as if it were a physical slice.

You can mirror any file system, including existing file systems. You can also use a mirror for any application, such as a database.

For planning information about RAID–1 volume requirements, see Mirror and Submirror Requirements and Guidelines.

For detailed information about RAID-1 volumes, see Solaris Volume Manager Administration Guide.