Hewlett Packard Enterprise HPE XP7, User Manual, Page: 29 / 311

Fast Snap pair restoration
Overwriting snapshot data to P-VOLs is also referred to as restoring Fast Snap pairs.
If data is written to a secondary volume, this particular data (not snapshot data) is overwritten to the
primary volume when the Fast Snap pair is restored.
If a problem occurs in P-VOL data due to a failure, restoring the pair restores the P-VOL data saved when
the snapshot data was stored. However, if the pair status is PSUE, the pair cannot be restored.
The time for restoring a Fast Snap pair depends on the following, even if the pair synchronization rate is
100%:
• The amount of pool capacity a pair is using.
• The number of pairs being operated concurrently.
The pair synchronization rate shows the rate that S-VOL data matches that of the next generation of the
S-VOL. If the S-VOL is the latest one, the synchronization rate is computed by comparing the S-VOL with
the P-VOL.
For the Fast Snap pair where the cascade attribute is enabled, the information displayed in
Synchronization Rate (%) of the View Pair Synchronization Rate window varies depending on the pair
status.
More information
Restoring Fast Snap pairs on page 124
How Fast Snap pair status changes
The following figure illustrates status changes to Fast Snap and snapshot pairs.
Fast Snap pair restoration 29