System requirements

External storage systems

UVM software license

Required. For installation and operations instructions, see the System Administrator Guide for your storage system.

RAID level

The RAID level for all external volumes is RAID 1. RAID 1 is displayed or used in the following cases:

• Internal processing of the local storage system
• Information about the external storage system that is reported to a host

Note: The local storage system uses RAID 1 cache management for external volumes. However, the external storage controller manages the physical RAID method. In addition, a hyphen is displayed instead of the RAID level in Device Manager - Storage Navigator windows.

Maximum number of ports in external storage systems that can be mapped

• Fibre Channel: 1,024 for each port
• iSCSI: 512 for each port (127 or less is recommended)

Maximum number of external volumes that can be mapped

• VSP 5000 series: 63,232
• VSP E590: 32,767
• VSP E790: 49,151
• VSP E990, VSP E1090: 65,279
• For Thin Image and Dynamic Provisioning, the total number of external and virtual volumes must not exceed the maximum number for each storage system model.

Maximum number of external volume groups

16,384

Maximum number of external volumes registered in each external volume group

4,096

Number of mapping paths

• One required
• Two or more recommended
• Maximum = 8 per external volume

Minimum capacity of an internal volume (VSP 5000 series)

The minimum capacity of an internal volume depends on the emulation type. See LDEV capacities per emulation type.

Maximum capacity of an internal volume (VSP E series)

If mapping an external volume of up to 4TB in an external storage system, the internal volume will be defined as 1 LDEV (LU), which is the same as the external volume.

You cannot access data that exceeds the maximum capacity of the external volume.

Maximum capacity of an external volume

256 TB (549,755,813,888 blocks) per external volume

You can create a volume larger than 256 TB, but can only use 256 TB as a mapped external volume. Data in the additional area cannot be accessed.

Minimum capacity of an external volume

• When the attribute of the data direct map is enabled, the capacity is 16,777,216 blocks (about 8,192 MB) for each external volume.
• When the attribute of the data direct map is disabled, the capacity is 96,000 blocks (about 47 MB) for each external volume.

Maximum number of external volumes that can be mapped per port

If one external port is connected to several target ports through switches, the maximum number of LUs defined for the connected target ports is 4,096.

Maximum LDEV capacity which can be created from an external volume

• If creating an LDEV from an external volume for which data direct mapping is enabled:

  256 TB (549,755,813,888 blocks) per external volume

• If creating an LDEV from an external volume for which data direct mapping is not enabled:

  4 TB (8,589,934,592 blocks) per external volume

For details about mapping using virtual volumes for which data direct mapping is enabled, see the Provisioning Guide.

• Direct connection:
  • 500 m (shortwave)
  • 10 km (longwave)
• Fibre Channel-switch cascade: 30 km (longwave)
• Extender: 100 km (recommended)

For more information, see External path configurations - direct, switch, and extender.