HP XP External Storage Software - Manual (Page 122)

Table 30 Restrictions on Remote Command Device
Restriction Item
OPEN-V Emulation type
1 Number of LDEVs in an external volume
Disable Cache mode
96,000 Blocks (about 47 MB) Minimum capacity
4 TB Maximum capacity
•
The remote command device cannot be identified by the port discovery or volume discovery
of XP External Storage.
•
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
ID on the port in the external storage system (A).
•
You cannot execute I/Os to the remote command device.
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You cannot set the command device disable on the remote command device.
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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.
Mapping a Command Device as a Remote Command Device
The command devices that can be mapped as remote command devices appear in the Device
column of the Volume Operation window as shown in
Table 29 (page 121) .
To map a command device, select a command device that can be mapped and follow the procedure
in
“Mapping an External Volume Automatically” (page 67) .
Using XP Continuous Access or XP Continuous Access Journal with Remote
Command Device
When you want to use XP Continuous Access or XP Continuous Access Journal with a remote
command device, you need two different kinds of ports, which are an initiator port for XP Continuous
Access or XP Continuous Access Journal and an external port for the remote command device.
However, if you set the Initiator/External MIX mode, you will be able to use a port as both initiator
port for XP Continuous Access or XP Continuous Access Journal and external port only for the
remote command device.
Before you set the Initiator/External MIX mode, you need to prepare initiator ports and external
ports in one port block of the Standard mode. You can set the Initiator/External MIX mode on the
port block that consists of the initiator ports and external ports.
Figure 42 (page 123) shows the difference between the Standard mode and Initiator/External MIX
mode. When the Standard mode is set to the ports, you have to connect the cables for both initiator
port and external port. However, if you set the Initiator/External MIX mode, you just need to connect
one cable, and you can use XP Continuous Access or XP Continuous Access Journal and remote
command device.
122 Remote Command Devices