Failure recovery, Requirements, restrictions, and notes – HP XP P9500 Storage User Manual
Page 138
Related information
•
•
“Requirements, restrictions, and notes ” (page 138)
•
“Setting up the 3 Cnt Ac-J Z DC multi-target configuration” (page 138)
Failure recovery
In a 3DC multi-target configuration with three Cnt Ac-J Z sites, failure recovery proceeds as follows:
•
If a failure occurs in the local site, business operations are moved to one of the remote sites.
When the failure is corrected at the local site, business operations are transferred back to the
local site.
•
If a failure occurs between the local site and one of the remote sites, business operations are
moved to the pair volume on the healthy remote site. When the failure is corrected, business
operations are transferred back to the local site.
Requirements, restrictions, and notes
•
The P9500 system at the three sites require registration of two mirrors in one journal (since
two pairs use the same volume). This is done using the Edit Journal Volumes dialog box in
Remote Web Console, and is discussed in the setup procedure.
•
To maintain consistency among the pairs in related journals, make sure that all data volumes
in the journals are used in pairs (with accompanying registered mirrors). If a data volume in
the local site journal, for example, is not used in a pair, the number of data volumes in the
journal may not be the same as the number in the secondary journal, and so consistency
cannot be maintained.
•
The P-VOL in the first pair cannot be in Pending status when creating the second pair. In this
case, the second pair will not be created.
•
When multiple mirrors are registered in the journal, the P-VOL of one of the mirrors cannot be
in Pending status when resynchronizing a pair of another mirror. In this case, the second pair
will not be resynchronized.
Setting up the 3 Cnt Ac-J Z DC multi-target configuration
Set up a 3 Cnt Ac-J Z DC multi-target configuration using the following procedure.
To set up a 3DC multi-target using Cnt Ac-J Z and Continuous Access Synchronous Z, see
for setting up 3DC multi-target” (page 148)
.
1.
Set up Cnt Ac-J Z at the primary and two remote sites, and configure ports. See:
“Configuring local and remote systems for Cnt Ac-J Z ” (page 60)
“Defining fibre-channel port attributes ” (page 59)
2.
Configure Cnt Ac-J Z journals in three three sites. When you register a journal, CAJ Z 3DC is
automatically enabled in the Edit Journal Volumes dialog box. This setting allows registration
of two MUs in a journal, as required for the intermediate S-VOL/P-VOL. See
journal volumes in a journal ” (page 65)
for more information about registering journals.
NOTE:
The Edit Journal Volumes setting, CAJ Z 3DC, cannot be changed in the dialog box.
To disable, it is necessary to delete the journal, disable the setting, and then register the journal
again.
3.
Create a pair in the first mirror, from the local site to a remote site. Specify a value from 0 to
3 as the Mirror ID.
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3 Cnt Ac-J Z data-center configurations