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
Figure 8. Local consistency group with global visibility
Properties of consistency groups
Properties of a consistency group are applied to all the virtual volumes in the consistency group.
All consistency groups have configurable properties that determine I/O behavior, including:
● Visibility
● Storage-at-clusters
● Detach-rule
● Auto-resume-at-loser
● Virtual-volumes
Visibility
Visibility controls which clusters know about a consistency group.
NOTE:
Visibility for consistency groups differs from the visibility property for devices. Devices can have visibility set to
local (visible only to the local cluster) or global (visible to both clusters). All distributed devices have global visibility.
By default, a consistency groups’s visibility property is set only 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.
The visibility of the volumes within the consistency group must match the visibility of the consistency group.
If the visibility of a volume in a consistency group is set to local, the visibility of the consistency group cannot be set to include
other clusters. For example, if volume LocalVolume with visibility property set to local is added to consistency group TestCG
the visibility of TestCG cannot be modified to include other clusters.
In general, visibility is set to one of three options:
● Configure the consistency group to contain only volumes that are local to the local cluster.
● Configure the consistency group to contain only volumes that have storage at one cluster, but have global visibility.
● Configure the consistency group to contain only volumes that are distributed with legs at both clusters.
Consistency Groups
67