64 Using the Snapshot Feature• Define the number of physical disks, but not specific physical disks, for therepository virtual disk.When using the create snapshotVirtualDisk command to create a snapshotvirtual disk, the standard virtual disk name for the source virtual disk is theminimum information required. When you provide only the standard virtualdisk name, the storage management software provides default values for theother required property parameters for a snapshot virtual disk.NOTE: In some cases, depending on the host operating system and any virtual diskmanager software in use, the software prevents you from mapping the same host toboth a source virtual disk and its associated snapshot virtual disk.An error message appears in the command line when the utility cannotdistinguish between the following:• Source virtual disk and snapshot virtual disk (for example, if the snapshotvirtual disk has been removed)• Standard virtual disk and virtual disk copy (for example, if the virtual diskcopy has been removed)If you are running a Linux operating system, run the hot_add utility toregister the snapshot virtual disk with the host operating system.NOTE: The hot_add utility is not available for Windows.Enabling the Snapshot Virtual Disk FeatureThe first step in creating a snapshot virtual disk is to make sure the feature isenabled on the storage array. You need a feature key to enable the feature. Thecommand for enabling the feature key file is:enable storageArray feature file="filename"where the file parameter is the complete file path and file name of a validfeature key file. Enclose the file path and file name in quotation marks (" ").Valid file names for feature key files usually end with .key extension.Creating a Snapshot Virtual Disk with User-Assigned Physical DisksCreating a snapshot virtual disk by assigning the physical disks allows you tochoose from the available physical disks when defining your storage arrayconfiguration. When you choose the physical disks for your snapshot virtualdisk, you automatically create a new disk group. You can specify whichphysical disks to use and the RAID level for the new disk group.
