Dell POWERVAULT MD3620I Manuel d'utilisateur télécharger pdf (Page 52)

52 Planning: MD3600i Series Storage Array Terms and Concepts

Snapshots are used to recover previous versions of files that have changed

since the snapshot was taken. Snapshots are implemented using a copy on

write algorithm, which makes a backup copy of data the instant a write occurs

to the virtual disk. Data on a virtual disk is copied to the snapshot repository

before it is modified. Snapshots can be created instantaneously or can be

scheduled and take up less overhead than a full physical copy process.

Snapshot Repository Virtual Disk

When you create a snapshot virtual disk, it automatically creates a snapshot

repository virtual disk. A snapshot repository is a virtual disk created in the

storage array as a resource for a snapshot virtual disk. A snapshot repository

virtual disk contains snapshot virtual disk metadata and copy-on-write data

for a particular snapshot virtual disk. The repository supports one snapshot

only.

You cannot select a snapshot repository virtual disk as a source virtual disk or

as a target virtual disk in a virtual disk copy. If you select a snapshot source

virtual disk as the target virtual disk of a virtual disk copy, you must disable all

snapshot virtual disks associated with the source virtual disk.

CAUTION: Before using the Snapshot Virtual Disks Premium Feature in a

Windows Clustered configuration, you must 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.

CAUTION: 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 misidentifying the snapshot virtual disk. This can result in

data loss or an inaccessible snapshot.

For more information on mapping the snapshot virtual disk to the secondary

node, see the Dell PowerVault MD3600i and MD3620i Storage Arrays With

Microsoft Windows Server Failover Clusters on dell.com/support/manuals.

Virtual Disk Copy

Virtual disk copy is a premium feature to:

•Back up data

• Copy data from disk groups that use smaller-capacity physical disks to disk

groups using greater capacity physical disks

book.book Page 52 Tuesday, June 18, 2013 3:09 PM

1 2 ... 47 48 49 50 51 52 53 54 55 56 57 ... 293 294

Pas de commentaire

Dell POWERVAULT MD3620I Manuel d'utilisateur Page 52