HP XP P9500 Storage - Manual (Page 149)

Thus:
•
Each site should have two command devices mapped via two target ports to the other two
sites.
•
Each site should also have two remote command devices mapped-to via external ports from
the other two sites.
The following illustration shows this command/remote command device configuration.
Figure 25 Remote command device configuration for delta resync
When mapping to remote command devices on each site is complete, you must assign mirror IDs
to the remote command devices. This is required to enable communication for delta resync
operations.
Assigning mirrors to remote command devices
The use of mirrors with remote command devices allows you to determine whether the delta resync
operation can be performed. You assign mirror IDs after setting up remote command devices as
described in the previous topic.
Prerequisites
•
To assign a mirror to a remote command device, the mirror’s status must be one of the following:
Initial, Active, Halt, Stopped, Hold, Holding, or Holding(Failure)
To use a mirror in Initial status, it must have mirror ID 00.
•
Perform this operation per journal.
•
In a journal, you can assign multiple mirrors to two remote command devices in one operation.
•
A maximum of 16 mirrors can be shared with a remote command device. When a remote
command device is shared, you can use it to do the following:
◦ Assign it to other mirrors
◦ Register it to an extended consistency group
◦
Use it with RAID Manager
When performing these functions with a remote command device, the number of registered
journals and instances used by RAID Manager are subtracted from the number of mirrors that
can be shared.
•
A maximum of 16 remote command devices can be used for the delta resync operation per
DKC.
Procedure 42 To assign mirror IDs to remote command devices
1. In Remote Web Console, select Actions > Remote Copy > Continuous Access Journal > Journal
Operation. The Journal Operation window displays.
Delta resync configuration 149