Fractional space reservation policies

Fractional space reservation policies include specific thresholds that determine when SnapManager must delete Exchange backup sets or unmount Exchange databases (or both), because the overwrite reserve utilization for the volume is running low.

If overwrite reserve space runs low for a fractional space-reserved volume, SnapManager prevents the overwrite reserve from becoming fully depleted.

• The default fractional space reservation policy
  SnapManager sets a default policy for fractional space reservation. You can use the default values, or change the values that would apply to all storage system volumes.
• Fractional space reservation policy settings
  The fractional space reservation policy settings enable you to indicate when SnapManager should begin automatically deleting Snapshot copies and unmounting Exchange databases due to overwrite reserve utilization. You can also specify how many Snapshot copies to retain.
• Configuring fractional space reservation policies
  You can enable fractional space reservation and also set the value of the fractional space reservation. With fractional reserve, the space reserved for overwrites is set to less than 100 percent of the total size of the space-reserved LUNs in a traditional volume or a flexible volume.