ShadowImage for Mainframe specifications

RAID level

All supported RAID levels are supported.

Pair volumes

• Number of P-VOLs per S-VOL: 1
• Number of S-VOLs per P-VOL: maximum of 3
• Maximum size of a P-VOL: maximum volume size in the storage system
• Maximum size of an S-VOL: maximum volume size in the storage system.
• Maximum size of all P-VOLs and S-VOLs: maximum size of all volumes that can be created in a storage system
• Supported volume types:
  • Internal volumes
  • External volumes configured by using Universal Volume Manager
  • Variable volume created by using Virtual LVI (CV). (The pair volumes must have the same capacity and emulation type.)
• Mirror Unit (MU) number: 0, 1, or 2 (The MU number is used for CCI operations.)
• Sharing pair volumes with other software applications: supported

  For details, see Sharing ShadowImage for Mainframe volumes with other software applications.

Maximum number of pairs

32,768 for a storage system (when one S-VOL is paired for a P-VOL). For details, see Determining the maximum number of ShadowImage for Mainframe pairs.

Consistency groups

• Maximum number of consistency groups per storage system: 2,048 (including SI, SIz, and TIA)
• Maximum number of consistency groups for SI and SIz: 128

  Note: You cannot place SI, SIz, and TIA pairs in the same consistency group.

• Maximum SIz pairs per consistency group: 8,192
• CTG IDs: 000 to 7FF

  CTG IDs 000 to 07F (0 to 127) are used for SI, SIz, and TIA.

  CTG IDs 080 to 7FF (128 to 2,047) are used only for Thin Image Advanced.

Note: When using BCM/PPRC, you need to reserve consistency group IDs by using the CCI raidcom modify ctg command before creating SIz pairs. When using CCI, you do not need to reserve consistency group IDs. You can cancel the reservation of a consistency group by using the CCI raidcom modify ctg command.

When creating SIz pairs by using CCI, you can specify the consistency group ID. If you do not specify a consistency group ID, the storage system automatically assigns a consistency group ID.

The consistency groups reserved for BCM/PPRC cannot be used by CCI. The consistency groups created by CCI cannot be used by BCM/PPRC.