Administrator Guide
Table Of Contents
- Dell EMC Storage Systems Administrator Guide for the metro node appliance
- Contents
- Preface
- CLI Workspace and User Accounts
- Meta Volumes
- System Management
- Thin support in metro node
- Provisioning Storage
- Volume expansion
- Data migration
- About data migrations
- Migrating thin-capable storage
- About rebuilds
- One-time data migrations
- Batch migrations
- Prerequisites
- Creating a batch migration plan
- Checking a batch migration plan
- Modifying a batch migration file
- Starting a batch migration
- Pausing/resuming a batch migration (optional)
- Canceling a batch migration (optional)
- Monitoring a batch migration’s progress
- Viewing a batch migration’s status
- Committing a batch migration
- Cleaning a batch migration
- Removing batch migration records
- Configure the WAN Network
- Cluster Witness
- Consistency Groups
- Performance and Monitoring
- Metro node with active-passive storage arrays
When a consistency group’s visibility is set to a cluster, the consistency group appears below /clusters/cluster-n/
consistency-groups context for the cluster.
NOTE: The context for a specified consistency group appears in a cluster’s consistency group CLI context only if the
Visibility property of the consistency group includes that cluster.
Under normal operations, the visibility property can be modified to expand from one cluster to both clusters.
Use the set command in /clusters/cluster/consistency-groups/consistency-group context to modify the
visibility property. If consistency group TestCG is visible only at cluster-1, use the set command to make it visible to cluster-1
and cluster-2:
VPlexcli:/clusters/cluster-1/consistency-groups/TestCG> set visibility
cluster-1,cluster-2
If a consistency group contains virtual volumes with a given visibility (for example, a member volume’s visibility is local), the
visibility property for the consistency group cannot be changed to conflict with the visibility property of the member virtual
volume.
For example, consistency group TestCG is visible only at cluster-1, and contains a volume V whose device is at cluster-1 and has
local visibility. Both the following commands will fail, because the volume V is not visible at cluster-2.
VPlexcli:/clusters/cluster-1/consistency-groups/TestCG> set visibility
cluster-1,cluster-2
VPlexcli:/clusters/cluster-1/consistency-groups/TestCG> set visibility cluster-2
Storage-at-clusters
Storage-at-clusters tells metro node at which cluster the physical storage associated with a consistency group is located.
The storage-at-clusters property of a consistency group must be a non-empty subset of the consistency group’s
visibility property.
● If visibility is set to one cluster, then storage-at-clusters must be exactly the same as visibility.
● If visibility is set to two clusters (1 and 2), then storage-at-clusters can be one of:
○ cluster-1
○ cluster-2
○ cluster-1 and cluster-2
A volume that does not have local storage at every cluster specified by the storage-at-clusters property of a consistency
group, cannot be added to the consistency group.
For example, if a volume has storage only at cluster-1, it cannot be added to a consistency group that has its storage-at-
cluster property set to cluster-1 and cluster-2.
A volume that has local storage at more clusters than those specified by the storage-at-clusters property of a
consistency group, cannot be added to the consistency group.
For example, if a volume has storage at cluster-1 and cluster-2, it cannot be added to a consistency group that has its
storage-at-cluster property set to cluster-1.
The storage-at-clusters property cannot be modified if doing so conflicts with the topology of any of the volumes
currently in the consistency group.
Use the set command in /clusters/cluster/consistency-groups/consistency-group context to modify the
storage-at-clusters property. For example, to set the storage-at-clusters property to both clusters:
VPlexcli:/clusters/cluster-1/consistency-groups/TestCG> set storage-at-clusters
cluster-1,cluster-2
NOTE: Best practice is to set the storage-at-clusters property when the consistency group is empty.
68 Consistency Groups