System requirements

Software license

The ShadowImage for Mainframe software license must be installed on the storage system.

License capacity

The capacity of P-VOLs and S-VOLs must be less than or equal to the installed license capacity. Volume capacity is counted only once, even if you use a volume more than once. You do not need to multiply the capacity by the number of times a volume is used. For example, a volume used as a P-VOL for three pairs is counted only once.

For an internal or external volume, the total volume capacity is counted. For a DP-VOL, the pool capacity being used by the volume is counted. For a volume with capacity saving enabled, the licensed capacity is the data capacity before saving. If the available licensed capacity will be exceeded when you create a pair, the pair create operation will fail.

After you start performing pair tasks, monitor your capacity requirements to keep the used capacity within the capacity of the installed license.

You can continue using ShadowImage for Mainframe volumes in pairs for 30 days after licensed capacity is exceeded, regardless of whether an external volume or a DP-VOL is used. After 30 days, the only allowed operation is pair deletion. The problem of exceeding the licensed capacity can be resolved by reducing the capacity to less than or equal to the licensed capacity. However, the warning message will remain displayed. The warning message is updated once a day, therefore when the problem is resolved, the warning message will automatically disappear within 24 hours.

For more information about licenses, see the System Administrator Guide.

User interfaces

• Command Control Interface (CCI) supports ShadowImage for Mainframe operations. The CCI software must be installed on a connected host. Embedded CCI (Command Console) does not support ShadowImage for Mainframe operations.
• Business Continuity Manager (BCM)

  BCM supports ShadowImage for Mainframe operations. The BCM software must be installed on a connected host machine. BCM command devices are required when operations are performed on systems that are not locally connected to the host.

• IBM^® PPRC

  You can perform ShadowImage for Mainframe operations using PPRC TSO and ICKDSF PPRCOPY commands.

  Note: You can use either BCM or IBM^® PPRC to perform ShadowImage for Mainframe operations. BCM and PPRC are independent functions. You must use either BCM or PPRC. There is no guard logic to prevent using both. Simultaneous use can cause unexpected results and errors because commands might be issued when states are not as expected.

• REST API

Pair volumes

• Supported volume types:
  • Internal volumes
  • External volumes
  • Customized volumes (CVs) that are created using Virtual LVI/LUN
• Emulation type: The supported emulation type (including Dynamic Provisioning for Mainframe volumes) is the same as when the pair status is SMPL/SIMPLEX. The P-VOL and S-VOL must have the same emulation type (for example, both 3390-9). The emulation type affects the number of differential and pair tables required.
• Volume capacity: The P-VOL and S-VOL must have the same capacity.
• The following volumes cannot be used as pair volumes:
  • URz journal volumes
  • Pool volumes
  • Command devices for Business Continuity Manager
  • TSE volumes
  • Volumes whose emulation type is 3390-V
  • Volumes for which Soft Fence is set