Manual
RequirementItem
Pair volumes
• Number of P-VOLs per S-VOL: one
• Number of S-VOLs per P-VOL: one to three
• Volume Capacity: P-VOL and S-VOLs must have the same capacity.
• Supported emulation types—See “Supported emulation types for pair volumes”
(page 12).
• Supported volume types:
- Internal system volumes.
- External volumes. External Storage (Ext Stor) license required.
- Custom-sized volumes. Virtual LVI required. Pair volumes must have same capacity
and emulation type.
• MU number (mirror unit number): Use 0, 1, or 2. Specified when using RWC and RAID
Manager, though not when using PPRC or BCM.
• Sharing volumes with other software products is supported. See “Sharing Business
Copy Z volumes” (page 24).
• The following cannot be used as pair volumes:
- Continuous Access Journal Z (Cnt Ac-J Z) journal volumes.
- Command devices for BCM.
• TSE volumes
• Volumes with emulation type 3390-V.
Per storage system: 16,384 pairs (when one S-VOL per P-VOL). Actual number is based
on amount of additional shared memory. See “Planning number of pairs” (page 15) for
further information.
Maximum number of pairs
Consistency groups
• You can configure up to 256 consistency groups in a storage system, including BC,
BC Z, Fast Snap (FS), and Snapshot (SS) consistency groups.
NOTE: BC, BC Z, FS, and SS pairs cannot co-exist in the same consistency group.
• You can define up to 8,192 BC Z pairs in a consistency group.
• A number (0–FF) is assigned to each consistency group. You specify a consistency
group number when you create pairs. If you do not specify a number, the storage
system automatically assigns it.
- Consistency group numbers 00 to 7F (or 0 to 127) that you can use for BC, BC Z,
FS, and SS. Consistency group numbers 80 to FF (or 128 to 255) are exclusively used
for FS and SS.
- PPRC/BCM consistency group numbers need to be reserved before creating a pair.
- If you are using RAID Manager, you do not need not to reserve consistency group
numbers.
• You cannot use consistency groups reserved for PPRC/BCM in RAID Manager.
Conversely, you cannot use consistency groups created using RAID Manager with
BCM/PPRC.
Supported emulation types for pair volumes
The emulation type of the P-VOL and S-VOLs must be the same. However, you can create a pair
from an intermediate volume and a normal volume if the two volumes are of the same type (such
as 3390-3 and 3390-3A/3390-3B).
12 Requirements and planning