Dell PowerVault MD3220 - Manual (Page 168)

168 Configuration: Premium Feature—Virtual Disk Copy
Creating a Virtual Disk Copy
CAUTION: Possible loss of data – 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 to be 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, make sure 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
If 16 virtual disk copies with the status of In Progress exist, any subsequent
virtual disk copy has the status Pending, which stays until one of the 16
virtual disk copies complete.
book.book Page 168 Tuesday, June 18, 2013 2:53 PM