Administrator Guide

Premium feature—virtual disk copy
NOTE: A virtual disk copy overwrites data on the target virtual disk. Before starting a virtual disk copy, ensure that you
no longer need the data or back up the data on the target virtual disk.
NOTE: If you ordered this feature, you received a Premium Feature Activation card that shipped in the same box as your
Dell PowerVault MD Series storage array. Follow the directions on the card to obtain a key file and to enable the feature.
NOTE: The preferred method for creating a virtual disk copy is to copy from a snapshot virtual disk. This allows the
original virtual disk used in the snapshot operation to remain fully available for read/write activity while the snapshot is
used as the source for the virtual disk copy operation.
When you create a virtual disk copy, you create a copy pair that has a source virtual disk and a target virtual disk on the same storage
array.
The source virtual disk is the virtual disk that contains the data you want to copy. The source virtual disk accepts the host I/O read
activity and stores the data until it is copied to the target virtual disk. The source virtual disk can be a standard or thin virtual disk.
The target virtual disk is a standard or thin virtual disk in a disk group or disk pool and, if the legacy version is enabled, a legacy snapshot
base virtual disk.
Reasons to use virtual disk copy include:
• Copying data for improved access—As your storage requirements for a virtual disk change, you can use a virtual disk copy to copy
data to a virtual disk in a disk group that uses physical disks with larger capacity within the same storage array. Copying data for larger
access capacity enables you to move data to greater capacity physical disks—for example, 61–146 GB.
• Restoring snapshot virtual disk data to the source virtual disk—The Virtual Disk Copy feature enables you first to restore the data
from a snapshot virtual disk and then to copy the data from the snapshot virtual disk to the original source virtual disk.
• Copying data from a thin virtual disk to a standard virtual disk residing in the same storage array. However, you cannot copy data in
the opposite direction—from a standard virtual disk to a thin virtual disk.
• Creating a backup copy—The Virtual Disk Copy feature enables you to create a backup of a virtual disk by copying data from one
virtual disk (the source virtual disk) to another virtual disk (the target virtual disk) in the same storage array, minimizing the time that
the source virtual disk is unavailable to host write activity. You can then use the target virtual disk as a backup for the source virtual
disk, as a resource for system testing, or to copy data to another device, such as a tape drive or other media.
NOTE:
Recovering from a backup copy—You can use the Edit Host-to-Virtual Disk Mappings feature to recover data
from the backup virtual disk you created in the previous procedure. The Host Mappings option enables you to unmap
the source virtual disk from its host and then to map the backup virtual disk to the same host.
Topics:
• Types of virtual disk copies
• Creating a virtual disk copy for an MSCS shared disk
• Virtual disk read/write permissions
• Virtual disk copy restrictions
• Creating a virtual disk copy
• Preferred RAID controller module ownership
• Failed RAID controller module
• Copy manager
• Copying the virtual disk
• Storage array performance during virtual disk copy
• Setting copy priority
• Stopping a virtual disk copy
• Recopying a virtual disk
• Removing copy pairs
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