Snapshot Schedules for a Virtual Machine

A snapshot schedule lets a VM take and keep snapshots automatically at set times. Keep these points in mind:

  • The shortest recommended interval between snapshots is 5 minutes (Scale Computing Support recommends no less than 15 minutes). Shorter intervals may cause unexpected behavior.
  • Keep overall system capacity in mind. Old snapshots can use a lot of capacity on active VMs.
  • One snapshot schedule can hold multiple recurrence rules.
  • A VM can only have one snapshot schedule assigned at a time.
  • You can set separate snapshot retention schedules on the Source and Target systems.
  • The Admin or Backup role to create, edit, or delete schedules.
  • The Admin role to assign a schedule to a VM. The Backup role can’t assign schedules (see User Access Control).

Snapshot Scheduling and Replication

VM replication uses snapshot schedules. A VM set up for replication uses the Replication Default schedule if no custom schedule is assigned. The Replication Default schedule takes a snapshot every 15 minutes. It keeps only the single latest snapshot once the previous one has been fully replicated.

If a virtual disk in the SC//HyperCore™ HyperVisor is cloned to a VM with a snapshot and/or replication schedule, the disk uses the VM’s schedule from then on.

If a custom snapshot schedule is already assigned to a VM when replication starts, replication follows the custom snapshot schedule. When replication is paused, the snapshot schedule pauses too: no snapshots will be taken while replication is paused. If a snapshot schedule is completely removed from an actively replicating VM, the VM will STOP replicating until a snapshot schedule is defined.

Deleting the Remote System Connection to the Target system stops the snapshot schedule of any VM that was replicating to it — the schedule stops running entirely, and no further snapshots are taken, local or replicated. Assigning the VM a snapshot schedule that does not replicate restarts local snapshots. But replication cannot resume until you add the Remote System Connection back and set up replication on the VM again. Pause or cancel replication on every affected VM before you remove a Remote System Connection. See Add, Monitor, or Remove a Remote System Connection.

If a custom snapshot schedule is assigned to a VM after replication has already been running, the VM goes on with the custom snapshot settings. Retention settings are set when each snapshot is taken, so a change to the snapshot schedule only applies to new snapshots. Existing snapshots keep their original retention rules.

Create, Edit, or Delete Snapshot Schedules and Schedule Rules

  1. Open the Control Center and select the Schedules tab.

Create:

  1. Click + Add Schedule. A popup dialog appears.
  2. Enter a Schedule Name.
  3. Click + Add Recurrence.
  4. In the popup dialog, enter a Name for the recurrence.
  5. Select a Frequency (minutely to monthly).
  6. Enter a recurrence period in the Every and At boxes.
  7. In the Keep For box, select how long to keep snapshots (this applies to Source system retention).
  8. Optional — Select Set Different Remote Retention if the Remote system needs a different retention period.
  9. Click Add to confirm the rule.
  10. Repeat steps 3–9 for each extra recurrence. To edit or remove a Recurrence Rule, use the Edit and Remove links under Options.
  11. Click Save on the Schedule dialog.

Edit:

  1. Click the Edit button to the right of the snapshot schedule you want to change.
  2. Make your changes.
  3. Click Save.

Delete:

  1. Click the Delete button to the right of the snapshot schedule you want to remove.
  2. If the schedule is in use on a VM, a warning appears. Click Delete Schedule to confirm.

Set Up a Snapshot Schedule on a Virtual Machine

  1. Go to the VM Management Panel.
  2. Open the Snapshots and Replication screen on the VM card.
  3. Click Select a Schedule (or Replication Default if replication is already configured). A popup dialog appears.
  4. In the Schedule dropdown list, select a snapshot schedule you created earlier.
  5. Click Update to confirm.

If a VM is shut down while a snapshot schedule is configured, the VM stops taking snapshots. It keeps its current snapshots and its memory of the snapshot schedule. When the VM is powered on again, it checks existing snapshots, removes any that have passed their retention level, and resumes taking new snapshots.

Remove a Snapshot Schedule from a Virtual Machine

  1. Go to the VM Management Panel.
  2. Open the Snapshots and Replication screen on the VM card.
  3. Click the name of the schedule. A popup dialog appears.
  4. In the dropdown list, select None.
  5. Click Update to confirm.