Dell POWERVAULT MD3600I - Manual (Page 168)

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 has been 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 appear. 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 appearing, 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 appearing.
The Virtual Disk Copy premium feature includes these items:
• The Create Copy Wizard, which assists in creating a virtual disk copy
• The Copy Manager, which monitors virtual disk copies after they are created
Setting Read/Write Permissions On Target Virtual Disk
To set read/write permissions on the target virtual disk:
1. In the AMW, click Storage & Copy Services.
2. Select Copy Services → Virtual Disk Copy → Manage Copies.
The Copy Manager window is displayed.
3. Select one or more copy pairs in the table.
4. Perform one of these actions:
– To enable Read-only permission, select Change → Target Virtual Disk Permissions → Enable Read-Only.
NOTE: Write requests to the target virtual disk are rejected when the Read-only permission is enabled
on the target virtual disk.
– To disable Read-only permission, select Change → Target Virtual Disk Permissions → Disable Read-Only.
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 eight virtual disk copies with a status of In Progress exist, any subsequent virtual disk copy has a status of Pending,
which stays until one of the eight virtual disk copies completes.
Virtual Disk Copy And Modification Operations
If a modification operation is running on a source virtual disk or a target virtual disk, and the virtual disk copy has a
status of In Progress, Pending, or Failed, the virtual disk copy does not take place. If a modification operation is running
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