Dell PowerVault MD3000 - Manual (Page 65)

Using the Snapshot Feature
65
Preparing Host Servers to Create an Initial Snapshot Virtual Disk
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 server has to be in the proper state.
To ensure that the host server is properly prepared to create a snapshot virtual
disk, 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.
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" in the User’s Guide 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 the Disk Groups & Virtual Disks
link.
4 Follow any additional instructions for your operating system. Failure to
follow these additional instructions can create unusable snapshot virtual
disks.
NOTE:
If your operating system requires additional instructions, you can find those
instructions in your operating system documentation.
If you want to use a snapshot regularly, such as for backups, use the Disable
Snapshot and Re-create Snapshot options to reuse the snapshot. Disabling
and re-creating snapshots preserves the existing virtual disk-to-host mappings
to the snapshot virtual disk.