Dell PowerVault MD3000 - Manual (Page 77)

Snapshot Virtual Disks 77
Before creating a Snapshot Virtual Disk, note the following:
• The following types of virtual disks are not valid source virtual disks:
snapshot repository virtual disks, snapshot virtual disks, target virtual disks
that are participating in a virtual disk copy.
NOTE: Virtual Disk Copy is an Advanced (Premium) feature.
• You cannot create a snapshot of a virtual disk that contains unreadable
sectors.
• You must satisfy the requirements of your host operating system for
creating snapshot virtual disks. Failure to meet the requirements of your
host operating system results in an inaccurate point-in-time image of the
source virtual disk or the target virtual disk in a virtual disk copy.
NOTICE: Before you create a new point-in-time image of a source virtual disk, stop
any data access (I/O) activity or suspend data transfer to the source virtual 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 will help to guarantee a stable copy of the
drive for the Snapshot.
Before creating a snapshot virtual disk, the host server has to be in the proper
state. Perform the following steps to prepare your host server:
1 Stop all I/O activity to the source.
2 Using your Windows system, flush the cache to the source. At the host
prompt, type
SMrepassist -f <filename-identifier>
and press <Enter>. See "SMrepassist Utility" on page 108 for more
information.
3 Remove the drive letter(s) of the source in Windows or unmount the
virtual drive(s) in Linux to help guarantee a stable copy of the drive for the
Snapshot. If this is not done, the snapshot operation will report that it has
completed successfully, but the snapshot data will not be updated properly.
NOTE: Verify that the virtual disk has a status of Optimal or Disabled by
clicking the Summary tab and then clicking Disk Groups & Virtual Disks.