Administrator Guide
Table Of Contents
- Dell EMC Storage Systems Administrator Guide for PowerStore and Unity XT metro node feature
- 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
- Consistency Groups
- Performance and Monitoring
- Metro node with active-passive storage arrays
- Index
Manage consistency groups
NOTE: A key best practice for creating and managing consistency groups is to create a 1:1 relationship between
consistency groups and applications. All volumes (and only those volumes) required for an application should be in a single
consistency group.
Creating a consistency group
Before you create a consistency group, consider its usage:
About this task
● At which clusters is the underlying storage of the virtual volumes located? If volumes are at both clusters, set the storage-
at-cluster property as cluster-1,cluster-2.
● What is the visibility of the virtual volumes to be added?
Some properties of virtual volumes and consistency groups limit which volumes can be added to a consistency group, or prevent
a property of the consistency group from being modified.
For example, a consistency group’s visibility property is set to cluster-1. Virtual volumes local to cluster-1 are added.
The visibility property of the consistency group cannot be changed to either cluster-2 or cluster-1,cluster-2
since the volumes are not visible at cluster-2.
To create a consistency group and to configure those properties that should be set before virtual volumes are added, perform
the following:
Steps
1. Use the ls /clusters/*/consistency-groups/ command to display the names of all the consistency groups:
VPlexcli:/> ls /clusters/*/consistency-groups/
/clusters/cluster-1/consistency-groups:
TestCG local_test test10 test11 test12 test13 test14
test15 test16 test5 test6 test7 test8 test9
vs_RAM_c1wins vs_RAM_c2wins vs_oban005 vs_sun190
/clusters/cluster-2/consistency-groups:
TestCG local_test test10 test11 test12 test13 test14
test15 test16 test5 test6 test7 test8 test9
vs_RAM_c1wins vs_RAM_c2wins vs_oban005 vs_sun190
2. Use the consistency-group create command to create a consistency group on a cluster. Specify a name for the new
consistency group that did not appear in the output in the previous step.
VPlexcli:/> consistency-group create --name TestCG --cluster cluster-1
3. Use the ls /clusters/cluster-id/consistency-groups/consistency-group/ command to display the new
consistency group.
Setting the visibility property
By default, the consistency group’s visibility property is set to the cluster where the consistency group was created. If
a consistency group is created on cluster-2, it is initially visible only on cluster-2.
Visibility can be configured as follows:
● cluster-1 - volumes local to cluster-1.
● cluster-2 - volumes local to cluster-2.
● cluster-1,cluster-2 - volumes that are distributed with legs at both clusters.
4. Use the set command to configure the consistency group’s visibility property.
CAUTION:
The CLI context of the consistency group appears only at the cluster where the consistency group
has visibility. If visibility is set from cluster-1 to include only cluster-2, the CLI context for the consistency
group disappears at cluster-1 and is visible only from cluster-2.
66 Consistency Groups