5–2 Configuring SnapShot
Hitachi Simple Modular Storage Copy-on-Write SnapShot User’s Guide
Configuration Workflow
The following configuration tasks must be completed for SnapShot functions
to become operational. The P-VOL should be set up in your Simple Modular
Storage system prior to SnapShot configuration. See Appendix B, SnapShot
Specifications for more information.
• Assign volumes for:
• Data pools
• Virtual volumes (V-VOL)
Assign Volumes for the Data Pool
The data pool stores differential data after the snapshot is created.
Differential data is the data in the P-VOL that is being updated. The original
data is stored in the data pool to retain the snapshot. For more information
on the data pool see Data Pools on page 1-6.
To create and assign volumes for data pools
(Advanced users using CLI, see Setting the POOL on page A-3.)
1. In Navigator 2 GUI, select the desired array, then click the Show &
Configure Array button.
2. From the Replication tree, select the Local Replication icon, then select
the Setup icon. The Setup screen displays.
3. Select Data Pools. View screen instructions by clicking the Help button.

Notes on Adding a Data Pool

• To review the data pool sizing procedure, see Establishing Data Pool
Size on page 2-5.
• Up to 64 volumes can be assigned to a data pool.
• Hitachi recommends a minimum of 20 GB for data pool size.
• The default Threshold value is 70%.
• When capacity reaches the Threshold plus 1 percent, both data
pool and pair status change to “Threshold over”, and the Storage
system issues a warning.
• If capacity reaches 100 percent, the pair fails and all data in the V-
VOL is lost.