Dell PowerVault MD3420 - Manual (Page 87)

Recopying A Virtual Disk
CAUTION: The recopy virtualDiskCopy command overwrites existing data on the target
virtual disk and makes the target virtual disk read
‑only to hosts. The recopy virtualDiskCopy
command fails all snapshot virtual disks associated with the target virtual disk, if any exist.
Using the recopy virtualDiskCopy command, you can create a new virtual disk copy for a
previously defined copy pair that has a status of Stopped, Failed, or Completed. Use the recopy
virtualDiskCopy command to create backups of the target virtual disk, then copy the backup to tape
for off-site storage. When using the recopy virtualDiskCopy command to make a backup, you
cannot write to source while the recopy is running. The recopy might take a long time.
When you run the recopy virtualDiskCopy command, the data on the source virtual disk is copied in
its entirety to the target virtual disk.
Reset the copy priority for the recopy operation by using the recopy virtualDiskCopy command.
The higher priorities allocate storage array resources to the virtual disk copy at the expense of storage
array performance.
Preparing Host Servers To Recopy A Virtual Disk
CAUTION: Before you create a new copy of a source virtual disk, stop any data access (I/O)
activity or suspend data transfer to the source virtual disk (and, if applicable, the target disk) to
ensure that you capture an accurate point-in-time image of the source virtual disk. Close all
applications, including Windows Internet Explorer, to make sure all I/O activity has stopped.
NOTE: Removing the drive letter of the associated virtual disk(s) in Windows or unmounting the
virtual drive in Linux helps to guarantee a stable copy of the drive for the virtual disk copy.
Before creating a new virtual disk copy for an existing copy pair, both the server and the associated virtual
disk you are recopying have to be in the proper state. To ensure that the host server is properly prepared
to create a virtual disk recopy, you can either use an application to carry out this task, or you can perform
the following steps:
1. Stop all I/O activity to the source and target virtual disk.
2. Using your Windows system, flush the cache to both the source and the target virtual disk (if
mounted). At the host prompt, type SMrepassist -f <filename-identifier> and press
<Enter>.
See "SMrepassist Utility" in the Owner’s Manual for more information.
3. Remove the drive letter(s) of the source and (if mounted) virtual disk in Windows or unmount the
virtual drive(s) in Linux to help guarantee a stable copy of the drive for the virtual disk. If this is not
done, the copy operation reports that it has completed successfully, but the copied data is not
updated properly.
4. Follow any additional instructions for your operating system. Failure to follow these additional
instructions can create unusable virtual disk copies.
NOTE: If your operating system requires additional instructions, you can find those instructions
in your operating system documentation.
After your server has been prepared, see Recopying The Virtual Disk to recopy the virtual disk.
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