Virtual disk read/write permissions, Virtual disk copy restrictions – Dell POWERVAULT MD3600I User Manual
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NOTE: When creating a snapshot virtual disk, map the snapshot virtual disk to only one node in the cluster.
Mapping the snapshot virtual disk to the host group or both nodes in the cluster may cause data corruption by
allowing both nodes to concurrently access data.
Virtual Disk Read/Write Permissions
After the virtual disk copy is complete, the target virtual disk automatically becomes read-only to the hosts. The target
virtual disk rejects read and write requests while the virtual disk copy operation has a status of Pending or In Progress
or if the operation fails before completing the copy. Keep the target virtual disk Read-only enabled if you want to
preserve the data on the target virtual disk for reasons such as the following:
•
If you are using the target virtual disk for backup purposes.
•
If you are using the data on the target virtual disk to copy back to the source virtual disk of a disabled or failed
snapshot virtual disk.
If you decide not to preserve the data on the target virtual disk after the virtual disk copy is complete, change the write
protection setting for the target virtual disk to Read/Write.
Virtual Disk Copy Restrictions
Before you perform any virtual disk copy tasks, understand and adhere to the restrictions listed in this section. The
restrictions apply to the source virtual disk, the target virtual disk, and the storage array.
•
While a virtual disk copy has a status of In Progress, Pending, or Failed, the source virtual disk is available for
read I/O activity only. After the virtual disk copy is complete, read and write I/O activity to the source virtual disk
are permitted.
•
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.
•
Snapshots created using older (legacy) premium feature versions cannot be managed using newer snapshot
premium feature options. A virtual disk in a snapshot group cannot be a target for a virtual disk copy.
NOTE: If you want to choose the base virtual disk of an older (legacy) snapshot virtual disk as your target
virtual disk, you must first disable all snapshot (legacy) virtual disks that are associated with the base
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.
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