Hitachi MK-96RD626-07 - Manual (Page 155)

Remote Command Devices 7-5
Hitachi Universal Storage Platform V/VM Universal Volume Manager User’s Guide
• Even if the status of the remote command device is normal, an error may
occur when the operations or commands are performed on the remote
command device.
If an error occurs even though the status of the remote command device is
normal, check the status of the command device of the external storage
system, not the remote command device.
• There are following restrictions for mapping a command device as a remote
command device.
Table 7-2 Restrictions on Remote Command Device
Item Restriction
Emulation type OPEN-V
Number of LDEVs in an external volume 1
Cache mode Disable
Minimum capacity 96,000 Blocks (about 47 MB)
Maximum capacity 4 TB
• The remote command device cannot be identified by the Port Discovery or
Volume Discovery of Universal Volume Manager.
• When an external storage system (A) has a remote command device (B)
(that is, when a command device in another external storage system (C) is
mapped to this external storage system (A)), make sure that the remote
command device (B) does not have the smallest LUN on the port in the
external storage system (A).
• You cannot execute I/Os to the remote command device.
• You cannot set the command device disable on the remote command
device.
• You cannot set the command device security on the remote command
device.
• Do not set the command device security on the external storage system
side for the command device that is mapped as a remote command device.
• You cannot create a LUSE volume using a remote command device.
• You cannot create CVs using the VLL function in the remote command
device.
• Cache Residency Manager is not available on the remote command device.