3.1.2 Matrix Server Administration Guide

Chapter 9: Manage Hardware Snapshots 134

when source filesystem data is changed. Snapshots can be fully-allocated

(the maximum amount of storage space is reserved at creation time), or

demand-allocated (the minimum amount of storage space is reserved at

creation time, allocating more as necessary). Snapshots are intended to be

temporary.

A snapclone is similar to a snapshot, except that it completely copies the

source filesystem data at a particular point in time. When you create a

snapshot, you can specify whether you want a fully-allocated snapshot, a

demand-allocated snapshot, or a complete-copy snapclone.

Snapshots can be both readable and writable and there can often be

multiple snapshots existing of a filesystem at a time.

To create a snapshot, select the filesystem on the Management Console,

right-click, and select Create Snapshot. (The filesystem must be

mounted.) You will then see a dialog asking for information specific to

your storage array.

The dialog describes the information that you will need to enter. When

you complete the information and click OK, Matrix Server takes these

steps:

• Quiesces the filesystem to ensure that the snapshot can be mounted

cleanly.

• Performs the snapshot operation using the snapshot capability

provided by the array. Matrix Server selects the next available LUNs

for the snapshot.

• Resumes normal filesystem activity.

• Imports the LUNs used for the snapshot into the matrix. The import

can take several moments.

When the snapshot is complete, you will be asked whether you want to

mount the snapshot. If you choose to do this, the Mount Filesystem

window will be displayed. (For information about the mount options, see

“Mount a Filesystem” on page 95.)

Snapshots appear on the Management Console beneath the entry for the

filesystem, while snapclones appear as a separate filesystem. Each