166 Configuration: Premium Feature—Virtual Disk Copy
• A virtual disk can be selected as a target virtual disk for only one virtual
disk copy at a time.
• A virtual disk copy for any virtual disk cannot be mounted on the same
host as the source virtual disk.
• Windows does not allow a drive letter to be assigned to a virtual disk copy.
• A virtual disk with a Failed status cannot be used as a source virtual disk or
target virtual disk.
• A virtual disk with a Degraded status cannot be used as a target virtual
disk.
• A virtual disk participating in a modification operation cannot be selected
as a source virtual disk or target virtual disk. Modification operations
include the following:
– Capacity expansion – RAID-level migration – Segment sizing
– Virtual disk expansion
– Defragmenting a virtual disk
NOTE: The following host preparation sections also apply when using the virtual
disk copy feature through the CLI interface.
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 might be rejected by the storage array, and an error message might 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
might not be issued due to the rejected write request. This condition might 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:
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