Configuration: Premium Feature—Snapshot Virtual Disks 157Scheduling a Snapshot Virtual DiskWhen you create a snapshot virtual disk, you can choose whether thesnapshot is created immediately or is created according to a schedule that youdetermine. This schedule can be a one-time snapshot creation or an ongoingsnapshot creation that occurs at regularly occurring intervals. If a schedule isnot specified, the snapshot virtual disk creation happens immediately uponexecution of the command.A schedule can be specified when a snapshot virtual disk is first created, or itcan be added to an existing snapshot virtual disk at any time. One scheduleper snapshot virtual disk is supported.Common Reasons for Scheduling a Snapshot Virtual DiskScheduling a snapshot virtual disk can serve multiple purposes across a datastorage environment. Most common uses of a snapshot scheduler are:• Data backups• Rapid recovery from a data loss eventA scheduled data backup can protect against data loss on a regular,unmonitored basis. For example, if an application stores business-critical dataon two virtual disks in the storage array, you may choose to perform anautomatic backup every day. To implement this backup, select the first virtualdisk and create a backup schedule that runs once a day, Monday throughFriday, at a time between the end of the work day and 11PM. Do not select anend date. Apply the same schedule to the second virtual disk, then map thetwo snapshot virtual disks to your backup host server and perform yourregular backup procedures. Remember to unmap the two resulting snapshotvirtual disks before the next scheduled snapshot begins. If the snapshotvirtual disks are not unmapped, the storage array does not perform the nextscheduled snapshot operation in order to avoid data corruption.Scheduled snapshots are also valuable in the event of a data loss. For example,if you back up your data at the end of every work day and keep hourlysnapshots from 8AM to 5PM, data can be recovered from the snapshots inwindows smaller than one hour. To accomplish this type of rapid recovery,create a schedule that contains a start time of 8AM and an end time of 5PM,then select 10 snapshots per day on Monday through Friday with no end date.
