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a. Select Provision Storage.
b. In the View by drop-down, select Consistency Groups.
2. In a metro node Metro:
a. Select Provision Storage.
b. In the Provision on drop-down, select the Distributed Storage.
c. In the View by drop-down, select Consistency Groups.
Create Consistency Group wizard
Use the Create Consistency Group wizard to a create a consistency group and add volumes to the group. You can create the
group and add the volumes later. Adding or removing a volume from a consistency group provides more information. Note the
following:
● You can create a maximum of 1,024 groups.
● There is a maximum of 1,000 volumes in a group.
● A volume can belong to only one consistency group at a time.
Configuring consistency groups
Consistency groups can consist of local, global, or distributed volumes. The following table describes the attributes that define
each type of consistency group.
Consistency Group Storage at Clusters Visibility
Local (Local volumes only) cluster-1 or cluster-2 cluster-1 or cluster-2
Global (Local volumes that are visible at both clusters) cluster-1 or cluster-2 cluster-1 and cluster-2
Distributed (Distributed volumes only) cluster-1 and cluster-2 cluster-1 and cluster-2
Choosing detach rules
When you add distributed volumes or volumes with global visibility to a consistency group, you must select a detach rule for the
group. The rule you select is applied to all volumes in the group and determines I/O behavior during an inter-cluster link failure.
The following table describes the predefined detach rules used for consistency groups, and the effect on I/O to volumes in the
group during a failure. You can change the detach rule at any time in the consistency group properties dialog box.
Detach Rule
Description Cluster-1 Cluster-2
Winner: cluster-x
delay_time. Where
delay_time = 5 seconds
(default)
Cluster-1 detaches cluster-2 if a link failure lasts more
than delay_time seconds. Note that the cluster that
detaches becomes the winner cluster and services I/O;
the cluster that gets detached becomes the loser cluster
and suspends I/O.
Services I/O Suspends I/O
Cluster-2 detaches cluster-1 if a link failure lasts more
than delay_time seconds. Note that the cluster that
detaches becomes the winner cluster and services I/O;
the cluster that gets detached becomes the loser cluster
and suspends I/O.
Suspends I/O Services I/O
No Automatic Winner Suspends I/O on both clusters. This detach rule is
generally used if you have created external scripts or use
other programs to determine which cluster detaches and
continues I/O during a link failure.
Suspends I/O Suspends I/O
Types of consistency groups
Consistency groups can consist of local, global, or distributed volumes. The following table describes the attributes that define
each type of consistency group.
Provisioning storage
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