Requirements and restrictions

• Global-active device license: The global-active device feature must be installed and enabled on the primary and secondary storage systems.
• Controller emulation type: The controller emulation type of the primary and secondary storage systems must be same.
• Shared memory: VSP E series and VSP G/F350, G/F370, G/F700, G/F900: You can use GAD only with shared memory in the basic part. Adding shared memory expands the capacity of the pairs being created.

• All storage systems in a GAD+UR configuration must be VSP 5000 series.

  Microcode: DKCMAIN version 90-01-00 or later

• 3DC delta resync in a GAD+UR configuration is supported only for VSP One Block 26, 28, VSP 5000 series, VSP E series, and VSP G/F350, G/F370, G/F700, G/F900.

• The storage system or server must be supported for attachment using Universal Volume Manager. The server must be attached using iSCSI.

  For details, see the Hitachi Universal Volume Manager User Guide for the storage system.

• The maximum distance between the external storage system and the primary site and secondary site is 1,500 km.

• The page size assigned to the virtual volume is counted as a licensed capacity for GAD; however, for a volume with capacity saving enabled, the GAD licensed capacity is the capacity before savings.
• If the actual licensed capacity exceeds the available licensed capacity, GAD can be used as usual for 30 days. After 30 days, only pair split and pair delete operations are allowed.

• AIX
• HP-UX
• OpenVMS
• Red Hat Enterprise Linux
• Solaris
• SuSE Linux
• VMware ESX
• Windows Server

• The Dynamic Provisioning function of Windows Server 2012 is supported.
• The SCSI-2 Reserve command, the SCSI-3 Persistent Reserve command, and the VAAI command are supported.
• In the environment with SCSI-3 Persistent Reserve enabled, a Reservation Key must be registered for each path (host group) on which an I/O operation is performed. Therefore, to perform an I/O operation from the host to both a P-VOL and an S-VOL, make sure to register a Reservation Key for each path (host group) of both the PVOL and the S-VOL. The registered Reservation Key information is duplicated between GAD pairs.

• Maximum number of physical paths: 8
• Maximum distance between the primary and secondary storage systems: 500 km
• The maximum value of the round-trip delay, including the delay due to the failure of an interface device, is 20 ms. However, you must meet the following conditions to connect storage systems over the distance of 100 km or more.
  • The primary and secondary storage systems are connected by Fibre Channel interfaces.
  • The DKCMAIN microcode version of the primary and secondary storage systems is 80-04-21-00/00 or later for VSP 5000 series and VSP G1x00, F1500.
  • The line speed between the primary and secondary storage systems is 1 Gbps or more.
  • The host mode option 51 is set to ON.
• Port type: Fibre Channel, iSCSI (VSP 5000 series 80-03-3x and later) with direct, switch, or channel extenders.

For details, see Connection types.

• Maximum number of remote paths per path group: 8
• Maximum number of path groups per storage system: 64 (sum of the path groups used by TC, UR, and URz)
• Path group ID: 0-255.
• Protocol: All remote paths in a path group must be the same protocol, either Fibre Channel or iSCSI. Remote paths for Fibre Channel and iSCSI cannot coexist within the same path group.
• If iSCSI is used in a remote path, the blocked path monitoring remote replica option must be set to at least 40 seconds (default). If blocked path monitoring is less than 40 seconds, the path might be blocked due to a delay in the network such as many switches in a spanning tree protocol (STP) network or a long distance connection.
• The path group is specified during the create pair operation and cannot be changed by resynchronization.
• The remote path must be set by each path group of the storage systems at the primary site and the secondary site.

  You can also use multiple path groups with the same combination of the storage systems at the primary and the secondary sites.

• When using the System connection type and not the CU connection type (specified on the Add Remote Connection window), specify different paths and path groups for TrueCopy, Universal Replicator, and Universal Replicator for Mainframe secondary storage systems.

• Maximum number of VSMs per storage system: 15
  • VSP One Block 26, 28, VSP 5000 series, VSP E series, and VSP G1x00, F1500: 15
  • VSP G/F350, G/F370, G/F700, G/F900: 7
• Maximum number of GAD volumes per VSM: 65,280
  • VSP One Block 26: 32,768
  • VSP One Block 28: 49,152
  • VSP 5000 series, VSP G1x00, VSP F1500, VSP G/F900, VSP E990: 65,280
  • VSP G/F350: 16,384
  • VSP G/F370: 32,768
  • VSP G/F700: 49,152
  • VSP E590, VSP E590H: 32,768
  • VSP E790, VSP E790H: 49,152
• You can create GAD pairs using volumes in virtual storage machines. When you want to create a GAD pair using volumes in VSMs, the VSM for the volume in the secondary site must have the same model and serial number as the VSM for the volume in the primary site.
• For VSP G200, G/F400, G/F600, G/F800, VSP G/F350, G/F370, G/F700, G/F900 when a resource group (virtual storage machine) in a storage system at the secondary site has the same virtual LDEV ID as the P-VOL, you cannot create a GAD pair. In addition, when a volume is not created and only LDEV IDs exist, virtual LDEV IDs must be deleted.

• DKCMAIN 80-02-xx or later: You can use a volume in a resource group that was migrated from a VSP or USP V/VM storage system to a VSP G1x00, F1500 as a GAD volume.
• DKCMAIN 80-01-xx or earlier: You cannot use a volume in a resource group that was migrated from a VSP or USP V/VM storage system to a VSP G1x00, F1500 as a GAD volume.

• When all pairs are created with DP-VOLs and external volumes (calculated by subtracting the number of quorum disks (at least one) from the maximum number of virtual volumes that can be defined in a storage system):
  • VSP One Block 26: 32,768
  • VSP One Block 28: 49,152
  • VSP 5000 series, VSP E series, VSP G1x00, F1500 and VSP G/F900 : 63,231
  • VSP G/F350: 16,382
  • VSP G/F370: 32,766
  • VSP G/F700: 49,150
• When CCI is used in the in-band method and all pairs are created with DP-VOLs or external volumes, and one virtual volume or external volume is used as a command device, and a volume is set for the quorum disk:
  • VSP One Block 26: 32,765
  • VSP One Block 28: 49,149
  • VSP 5000 series, VSP E series, VSP G1x00, F1500 and VSP G/F900 : 63,231
  • VSP G/F350: 16,382
  • VSP G/F370: 32,766
  • VSP G/F700: 49,150
• When CCI is used in the in-band method and all pairs are created with DP-VOLs or external volumes, one normal volume (VSP F400, F600, F800, VSP G200, VSP G400, G600, G800, VSP G/F350, G/F370, G/F700, G/F900) or internal volume (VSP 5000 series) is used as a command device, and a volume is set for the quorum disk: 63,231
  • VSP One Block 26: 32,765
  • VSP One Block 28: 49,149
  • VSP 5000 series, VSP E series, VSP G1x00, F1500 and VSP G/F900 : 63,231
  • VSP G/F350: 16,382
  • VSP G/F370: 32,766
  • VSP G/F700: 49,150
• When CCI is used in the in-band method and all pairs are created with DP-VOLs or external volumes, one virtual volume (DP-VOL) or external volume is used as a command device, and no volume is set for the quorum disk: VSP G1x00, 1500 : 63,231
• When CCI is used in the in-band method and all pairs are created with DP-VOLs or external volumes, one internal volume is used as a command device, and no volume is set for the quorum disk: VSP G1x00, F1500: 63,232
• When all pairs are created with internal volumes (calculated by subtracting the number of quorum disks (at least one) from the maximum number of internal volumes that can be defined in a storage system):
  • VSP One Block 26: 32,767
  • VSP One Block 28: 49,151
  • VSP 5000 series, VSP E series, VSP G1x00, F1500 and VSP G/F900 : 65,279
  • VSP G/F350: 16,383
  • VSP G/F370: 32,767
  • VSP G/F700: 49,151
• When all pairs are created with internal volumes, and no volume is set for the quorum disk, the maximum number of GAD pairs: VSP G1x00, F1500: 65,280
• When CCI is used in the in-band method and all pairs are created with internal volumes, and one virtual volume or external volume for VSP 5000 series, VSP G1x00, F1500 is used as a command device, and a volume is set for the quorum disk:
  • VSP One Block 26: 32,765
  • VSP One Block 28: 49,149
  • VSP 5000 series, VSP E series, VSP G1x00, F1500 and VSP G/F900 : 65,277
  • VSP G/F350: 16,381
  • VSP G/F370: 32,767
  • VSP G/F700: 49,149
• When CCI is used in the in-band method and all pairs are created with internal volumes, and one normal volume (VSP G200, G/F400, G/F600, G/F800, VSP G/F350, G/F370, G/F700, G/F900) or internal volume (VSP 5000 series) is used as a command device, and a volume is set for the quorum disk:
  • VSP One Block 26: 32,765
  • VSP One Block 28: 49,149
  • VSP 5000 series, VSP E series, VSP G1x00, F1500 and VSP G/F900: 65,278
  • VSP G/F350: 16,382
  • VSP G/F370: 32,766
  • VSP G/F700: 49,150
• When CCI is used in the in-band method and all pairs are created with internal volumes, and one virtual volume or external volume for VSP 5000 series or VSP G1x00, F1500 is used as a command device, and no volume is set for the quorum disk: VSP G1x00, F1500 : 65,278
• When CCI is used in the in-band method and all pairs are created with internal volumes, and one normal volume (VSP G200, G/F400, G/F600, G/F800, VSP G/F350, G/F370, G/F700, G/F900) or internal volume VSP 5000 series is used as a command device, and no volume is set for the quorum disk: VSP G1x00, F1500 : 65,279
• Virtual storage machine: same as the maximum number of pairs for the storage system model.

• Provisioning type: The following provisioning types are supported for the GAD pair volumes. The provisioning type of the P-VOL and S-VOL must be same. For example, if the P-VOL is a DP-VOL, the S-VOL must also be a DP-VOL.
  • Dynamic Provisioning virtual volumes (DP-VOLs)

    For DP-VOLs, you can only create a GAD pair when both DP-VOLs do not have the Data Direct Mapping attribute or when both DP-VOLs have the Data Direct Mapping attribute. You cannot create a GAD pair when the Data Direct Mapping attribute is enabled for one DP-VOL but not for the other.

  • Internal volumes
  • External volumes
• Emulation type: OPEN-V.
• Volume size: The P-VOL and S-VOL must be equal in size.
• Maximum volume size:

  DP-VOL: same as the maximum size of a DP-VOL. For details, see the Provisioning Guide for the storage system.

  VSP One Block 26, 28, VSP 5000 series, VSP G1x00, F1500

  • Internal volume: 3,145,663 MB (6,442,317,824 blocks)
  • External volume: 4,194,304 MB (8,589,934,592 blocks)

  (VSP E series, VSP G/F350, G/F370, G/F700, G/F900 )

  • Internal volume: 256 TB
  • External volume: 256 TB
• SAN boot: You can use GAD pair volumes for SAN boot.
• Virtual LDEV ID: The same virtual LDEV ID as the P-VOL must not exist in the resource group of the secondary storage system (virtual storage machine). You cannot create a GAD pair when the same virtual LDEV ID as the P-VOL exists in the resource group of the secondary storage system (virtual storage machine). To use the P-VOL, you must delete the virtual LDEV ID in the resource group of the secondary storage system. You must delete the virtual LDEV ID even if the volume is not created and only the LDEV ID exists.
• T10 PI: The same value must be set for the T10 PI attribute of the P-VOL and the S-VOL.
• A volume (LDEV) from a parity group with accelerated compression enabled cannot be used directly as a GAD pair volume. Such volumes must be used as pool volumes for an HDP or HDT pool.

• Maximum number of quorum disks: 32 per storage system in the primary storage system and secondary storage system.
• Quorum disk ID: Specify a value from 0 to 31.
• Maximum number of pairs per quorum disk:
  • VSP One Block 26: 32,765 when you create all pairs with DPVOLs or external volumes, and 32, 767 when you create all pairs with internal volumes.
  • VSP One Block 28: 49,149 when you create all pairs with DPVOLs or external volumes, and 49,151 when you create all pairs with internal volumes.
  • VSP 5000 series, VSP G1x00, F1500 : 63,231 when you create all pairs with DP-VOLs or external volumes, and 65,279 when you create all pairs with internal volumes.
  • VSP G150, VSP G/F350: 16,382 when you create all pairs with DP-VOLs or external volumes, and 16,383 when you create all pairs with internal volumes.
  • VSP G/F370: 32,766 when you create all pairs with DP-VOLs or external volumes, and 32,767 when you create all pairs with internal volumes.
  • VSP G/F700: 49,150 when you create all pairs with DP-VOLs or external volumes, and 49,151 when you create all pairs with internal volumes.
  • VSP G/F900: 63,232 when you create all pairs with DP-VOLs or external volumes, and 65,279 when you create all pairs with internal volumes.
  • VSP E series: 63,232 when you create all pairs with DP-VOLs or external volumes, and 65,279 when you create all pairs with internal volumes.
• Emulation type:

  VSP One Block 20, VSP 5000 series, VSP E series, VSP G1x00, F1500: OPEN-V

• Minimum size: 12,292 MB (25,174,016 blocks)
• Maximum size: same as the maximum limit for an external volume supported by Universal Volume Manager: 4 TB.
• In addition to a volume in an external storage system, a disk in an iSCSI-attached server can be used as a quorum disk if the server is supported by Universal Volume Manager.

  Note: The server and storage systems are connected using iSCSI.

  See the Hitachi Universal Volume Manager User Guide for details.

• One external volume group must be mapped to one external volume.
• Interoperability: A GAD quorum disk cannot also be used as a quorum disk with High Availability Manager for VSP, HUS VM, and USP V/VM.
• Requirements for the external storage system volume:
  • The T10 PI attribute must not be enabled.
  • The Data Direct Mapping attribute must not be set.
• The maximum number of GAD groups that are allowed for a quorum disk is 1,024 (VSP 5000 series, VSP G1x00, F1500).

• Maximum number of consistency groups per storage system:
  • VSP One Block 26, 28: 128 (CTG ID 0-127)
  • VSP 5000 series: 1,024 (CTG ID 0-1023)
  • VSP E series, VSP G/F900: 256 (CTG ID 0-255)
  • VSP G/F350, G/F370, G/F700, G/F900: 128 (CTG ID 0-127)
  • VSP G1x00, F1500
• Maximum number of GAD pairs per consistency group:
  • VSP One Block 26, 28: 8,192
  • VSP 5000 series , VSP E series, VSP G1x00, F1500 : 8,192
  • VSP G/F350, G/F370, G/F700, G/F900: 8,192

  When different storage system models are connected, the smaller maximum number is applied (for example, the maximum is 128 when VSP G350 and VSP G900 are connected).

• Quorum disk ID: The same quorum disk ID must be set for all GAD pairs in a single consistency group.
• VSM: GAD pairs in the same consistency group must be created on the same virtual storage machine.
• CTG ID: If consistency groups have the same ID but their physical storage systems are different, they are treated as different consistency groups. You can use the same consistency group ID for groups on different storage systems.

Alternate path software is required for the single-server GAD configuration and the cross-path GAD configuration (two servers). When ALUA is used in the cross-path configuration, use the same models at both the primary and secondary sites.

Refer to the Hitachi Vantara interoperability matrix: https://support.hitachivantara.com/en_us/interoperability.html

Cluster software

Cluster software is required for the server-cluster and cross-path GAD configurations.

See the Hitachi Vantara interoperability matrix: https://support.hitachivantara.com/en_us/interoperability.html

• VSP One Block Administrator: Use VSP One Block Administrator to configure the remote paths and the quorum disk required when using global-active device for VSP One Block storage systems. You must configure these settings on the primary and secondary storage systems in the global-active device environment.
• Storage Advisor Embedded: For VSP E series, VSP G/F350, G/F370, G/F700, G/F900: firmware 88-03-0x or later, use Storage Advisor Embedded to configure the remote paths and the quorum disk required for using global-active device. These settings must be configured on the primary and secondary storage systems in the global-active device environment.
• Storage Navigator: Storage Navigator must be connected to the primary and secondary storage systems.
• Command Control Interface: version 01.32.00 or later.
  • VSP One Block: 01-75-03/03
  • VSP 5000 series, VSP G1x00, F1500: 01-32-03/00 or later
  • VSP E series: 01-53-03/xx or later
  • VSP G/F350, G/F370, G/F700, G/F900: 01-45-03/02 or later

  CCI must be installed on the host connected to the primary and secondary storage systems.

  The CCI command device is required on the primary and secondary storage systems.

• Ops Center Administrator

  Use Ops Center Administrator to configure and manage virtual storage machine (VSM), GAD pairs, and monitor and manage your global-active device environment.

• Ops Center Protector

  Use Ops Center Protector to perform pair operations in a global-active device environment.

• The number of LU paths that can be created can be up to 4096 for VSP 5000 series, VSP G1x00, F1500 with a DKCMAIN program version of 90-02-0x-xx/xx or later.
• The number of LU paths that can be created when connecting a VSP 5000 series, VSP G1x00, F1500 with an earlier DKCMAIN program version is limited to 2048.
• The number of LU paths that can be created when connecting a different source storage system is limited to 2048.