Administering Schedules

A schedule is a group of rules that specify recurring points in time at which certain actions are determined to occur. You can use schedules to automate the creation of snapshots and mirrors and the offload of volume data to a storage tier; after you create a schedule, it appears as a choice in the scheduling menu when you are creating or editing a volume.

When you specify a snapshot schedule on a mirror volume, it specifies how often to take a snapshot of the mirror volume. This snapshot schedule is distinct from the snapshot schedule for the standard volume. A snapshot schedule for a promotable mirror volume has two purposes:

• It specifies how often to take a snapshot of the mirror volume for the purpose of preserving the state of the mirror before a subsequent mirror operation. This way, if corrupt data is copied from the source volume's snapshot into the mirror volume, the mirror contents can be rolled back to the snapshot.
• If the promotable mirror volume is promoted to a read-write volume, the snapshot schedule specified for the mirror is used for the promoted read-write volume. Once a mirror volume is promoted to a read-write volume, the mirror schedule is disabled.

A mirror schedule specifies how frequently the mirror volume is synchronized with the source volume. In case of a disaster (or any type of data loss on a read-write source volume), the data can be recovered from the mirror volume, but any data written to the source volume since the last successful mirror operation will not be on the mirror volume. Therefore, you should set the mirror schedule such that it meets your RPO (Recovery Point Objective).

A tier offload schedule specifies how frequently data in the volume on the fabric is offloaded to the tiered storage. This setting to automatically offload data to the storage tier.