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
General procedure to perform data migration
Use the following general steps to perform device migrations:
1. Create and check a migration plan (batch migrations only).
2. Start the migration.
3. Monitor the migration progress.
4. Pause, resume, or cancel the migration (optional).
5. Commit the migration. Commit transfers the source virtual volume, device to the target.
If the virtual volume on top of a device has a system-assigned default name, committing a device migration renames the
virtual volume after the target device.
6. Remove the record of the migration.
Prerequisites for target devices
The target device must:
● Be the same size or larger than the source device.
If the target is larger in size than the source, the extra space can be utilized by using storage volume expansion, if all the
prerequisites for storage volume expansion are met.
For example, if the source is 200 GB, and the target is 500 GB, only 200 GB of the target can be used after a migration. The
remaining 300 GB can be claimed by performing a storage volume expansion, if supported by the virtual volume.
● Not have any existing volumes on it.
WARNING:
Device migrations are not recommended between clusters. All device migrations are synchronous.
If there is I/O to the devices being migrated, and latency to the target cluster is equal to or greater than
5ms, then significant performance degradation could occur.
Migrating thin-capable storage
The following table describes the migration scenarios that are supported and the state of the virtual volumes before, during, and
after the migration.
Table 5. Migration scenarios
Migration Virtual volume state before
migration
Virtual volume state during
migration
Virtual volume state after
migration
Thick to thin Thin-capable = false Thin-capable = false Thin-capable = true
Thin-enabled = unavailable Thin-enabled = unavailable Thin-enabled = disabled
UNMAP rejected UNMAP rejected UNMAP rejected
NOTE: You must set
the thin-enabled value to
true before UNMAP is
processed.
Thin to thin (Thin-enabled
virtual volume)
Thin-capable = true Thin-capable = true Thin-capable = true
Thin-enabled = enabled Thin-enabled = enabled Thin-enabled = enabled
UNMAP processed UNMAP processed UNMAP processed
Thin to thin (Mixed storage
array family)
Thin-capable = true Thin-capable = false UNMAP rejected
Thin-enabled = enabled Thin-enabled = enabled UNMAP rejected
Thin to thin (Non thin-enabled
virtual volume)
Thin-capable = true Thin-capable = true Thin-capable = true
Thin-enabled = disabled Thin-enabled = disabled Thin-enabled = disabled
UNMAP rejected UNMAP rejected UNMAP rejected
38 Data migration