Dell PowerVault MD3820f - Manual (Page 110)

The Total Unconfigured Capacity node, shown in the Storage & Copy Services tab, is a contiguous
region of unassigned capacity on a defined disk group. When increasing virtual disk capacity, some or all
of the free capacity may be used to achieve the required final capacity. Data on the selected virtual disk
remains accessible while the process for increasing virtual disk capacity is in progress.
Using Unconfigured Capacity
You can increase the capacity of a standard virtual disk or a snapshot repository virtual disk using the
unconfigured capacity when no free capacity exists on a disk group. An increase is achieved by adding
unconfigured capacity, in the form of unassigned physical disks, to the disk group of the standard virtual
disk or the snapshot repository virtual disk. See
Disk Group Expansion .
For more information, see the online help topics.
Disk Group Migration
Disk group migration allows to you to migrate a disk group by exporting a disk group and then importing
it to another storage array. You can also export a disk group to store data offline.
When you export a disk group, all the physical disks become offline. To ensure that the export is
successful, at least two physical disks that are not part of the disk group you are migrating must be
present in the storage array.
When you migrate the exported disk group to the new storage array, the import fails if a majority of the
physical disks are not present in the group. For example, both the physical disks in a two-disk RAID 1
configuration, or three physical disks (one from each disk pair) in a four-disk RAID 10 configuration must
be present.
Export Disk Group
The export disk group operation prepares the physical disks in the disk group for removal. You can
remove the physical disks for offline storage, or you can import the disk group to a different storage
array. After you complete the export disk group operation, all of the physical disks are offline. Any
associated virtual disks or free capacity nodes are no longer shown in the MD Storage Manager.
Non-Exportable Components
You must remove or clear any non-exportable settings before you can complete the export disk group
procedure. Remove or clear the following settings:
• Persistent reservations
• Host-to-virtual disk mappings
• Virtual disk copy pairs
• Snapshot virtual disks and snapshot repository virtual disks
• Remote mirror pairs
• Mirror repositories
Exporting A Disk Group
On the source storage array:
1. Save the storage array configuration.
2. Stop all I/O, and unmount or disconnect the file systems on the virtual disks in the disk group.
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