Volume sets have the following limitations:

• A maximum of 2048 volumes can be configured in a volume set.

• Only a Veritas File System is supported on a volume set.

• The first volume (index 0) in a volume set must be larger than the sum of the total volume size divided by 4000, the size of the VxFS intent log, and 1MB. Volumes 258 MB or larger should always suffice.

• Raw I/O from and to a volume set is not supported.

• Raw I/O from and to the component volumes of a volume set is supported under certain conditions.

• Resizing a volume set with an unmounted file system is not supported.

• Volume sets can be used in place of volumes with the following vxsnap operations on instant snapshots: addmir, dis, make, prepare, reattach, refresh, restore, rmmir, split, syncpause, syncresume, syncstart, syncstop, syncwait, and unprepare. The third-mirror break-off usage model for full-sized instant snapshots is supported for volume sets provided that sufficient plexes exist for each volume in the volume set.

  For more information about snapshots, see the Veritas Storage Foundation Advanced Features Administrator's Guide.

• A full-sized snapshot of a volume set must itself be a volume set with the same number of volumes and the same volume index numbers as the parent. The corresponding volumes in the parent and snapshot volume sets are also subject to the same restrictions as apply between standalone volumes and their snapshots.