Dell PowerVault MD3220 - Manual (Page 147)

Configuration: Premium Feature—Snapshot Virtual Disks 147
– Dell recommends placing the snapshot repository virtual disk within
the disk group of the source virtual disk. This ensures that if drives
associated with the disk group are moved to another storage array, all
the virtual disks associated with the snapshot virtual disk remain in
the same group.
• Snapshot Repository Virtual Disk Capacity—The snapshot repository
virtual disk capacity is expressed as a percentage of the source virtual disk
capacity (maximum 220 percent).
• Percent Full—When the snapshot repository virtual disk reaches the user-
specified repository full percentage level, the event is logged in the Major
Event Log (MEL). The default snapshot repository full percentage level is
50% of the source virtual disk.
• Snapshot Repository Virtual Disk Full Conditions—Choose whether to
fail writes to the source virtual disk or fail the snapshot virtual disk when
the snapshot repository virtual disk becomes full.
• Host-to-Virtual Disk Mapping—Choose whether to map the snapshot
virtual disk to a host or host group now or to map the snapshot virtual disk
later. The default setting is Map later.
• Schedule—Creates the snapshot virtual disk at a specified time, or
according to a regularly occurring interval. If no schedule is specified, the
snapshot operation begins immediately. This parameter can also be used to
apply a schedule to an existing snapshot virtual disk.
Preparing Host Servers to Create the Snapshot Using the Advanced Path
NOTE: Before using the Snapshot Virtual Disks Premium Feature in a Microsoft
Windows clustered configuration, you must first map the snapshot virtual disk to
the cluster node that owns the source virtual disk. This ensures that the cluster
nodes correctly recognize the snapshot virtual disk.
NOTE: Mapping the snapshot virtual disk to the node that does not own the source
virtual disk before the Snapshot enabling process is completed can result in the
operating system mis-identifying the snapshot virtual disk. This, in turn, can result in
data loss on the source virtual disk or an inaccessible snapshot.
NOTE: For more information on mapping the snapshot virtual disk to the secondary
node, see the Dell PowerVault MD3200 and MD3220 Storage Arrays With Microsoft
Windows Server Failover Clusters at dell.com/support/manuals.
book.book Page 147 Tuesday, June 18, 2013 2:53 PM