Dell POWERVAULT MD3600F - Manual (Page 176)

174 Configuration: Premium Feature—Virtual Disk Copy
NOTE: The following host preparation sections also apply when using the virtual
disk copy feature through the CLI interface.
Creating a Virtual Disk Copy
Source virtual disks that are participating in a virtual disk copy are available
for read I/O activity only while a virtual disk copy has a status of In Progress or
Pending. Write requests are allowed after the virtual disk copy has completed.
If the source virtual disk is formatted with a journaling file system, any
attempt to issue a read request to the source virtual disk may be rejected by
the storage array, and an error message may be displayed. The journaling file
system driver issues a write request before it attempts to issue the read
request. The storage array rejects the write request, and the read request may
not be issued due to the rejected write request. This condition may result in
an error message being displayed, which indicates that the source virtual disk
is write protected.
To prevent this issue from occurring, do not attempt to access a source virtual
disk that is participating in a virtual disk copy while the virtual disk copy has a
status of In Progress. Also, ensure that the Read-Only attribute for the target
virtual disk is disabled after the virtual disk copy has completed to prevent
error messages from being displayed.
The Virtual Disk Copy premium feature includes:
• The Create Copy Wizard, which assists in creating a virtual disk copy
• The
Copy Manager, which monitors virtual disk copies after they are
created
Before You Begin
A virtual disk copy fails all snapshot virtual disks that are associated with the
target virtual disk, if any exist. If you select a source virtual disk of a snapshot
virtual disk, you must disable all of the snapshot virtual disks that are
associated with the source virtual disk before you can select it as a target
virtual disk. Otherwise, the source virtual disk cannot be used as a target
virtual disk.
A virtual disk copy overwrites data on the target virtual disk and automatically
makes the target virtual disk read-only to hosts.
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