Dell POWERVAULT MD3600I - Manual (Page 221)

19
System Interfaces
Virtual Disk Service
The Microsoft Virtual Disk Service (VDS) is a component of the Windows operating system. The VDS component utilizes
third-party vendor specific software modules, known as providers, to access and configure third-party storage
resources, such as MD Series storage arrays. The VDS component exposes a set of application programming interfaces
(APIs) that provides a single interface for managing disks and other storage hardware. The MD Series VDS Provider
enables Windows tools, including the Disk Manager, to access and configure storage array virtual disks.
The VDS Provider for the MD Series storage arrays is available on the MD Series resource DVD. For more information on
VDS, see microsoft.com.
Volume Shadow-Copy Service
The Microsoft Volume Shadow-copy Service (VSS) is a component of the Microsoft Windows operating system. The
VSS component utilizes third-party vendor specific software modules, known as providers, to access and utilize
snapshot and disk copy functionality provided by third-party storage resources, such as MD Series storage arrays. The
combination of the VSS component and the VSS Provider, included on the MD Series Resource media, enables the MD
Series storage arrays to be utilized by third-party and Windows backup and snapshot applications.
NOTE: Virtual disks used as source virtual disks for VSS snapshots must not have names longer than 16 characters.
The VSS hardware provider uses the source virtual disk name as a prefix for the snapshot and repository virtual disk
names. The resulting snapshot and repository names are too long if the source virtual disk name exceeds 16 characters.
VSS attaches to the service and uses it to coordinate the creation of snapshot virtual disks on the storage array. VSS-
initiated snapshot virtual disks can be triggered through backup tools, known as requestors. The VSS Provider
Configuration Tool makes available the following configuration options:
• Snapshot Repository Virtual Disk Properties — This section contains a drop-down list for the RAID level and a
field for entering source virtual disk capacity percentage for snapshot repositories.
• Snapshot Repository Virtual Disk Location — This section contains a list of preferences for the location of the
snapshot repository virtual disk. These preferences are honored whenever conditions permit.
The Microsoft VSS installer service for storage provisioning is available on the MD Series resource media in the
\windows\VDS_VSS directory.
NOTE: When registering VSS during your Windows setup, the registration graphical user interface (GUI) prompts
you to provide the name of your array because settings in the GUI are array-specific, not host-specific.
Storage Management VSS Hardware Provider tips:
• The number of snapshot virtual disks that can be created using a single snapshot set varies with the I/O load on
the RAID controller modules. Under little or no I/O load, the number of virtual disks in a snapshot set must be
limited to eight. Under high I/O loads, the limit must be three.
• The snapshot virtual disks created in the MD Storage Manager are differential snapshots. Plex snapshots are
not supported.
• Virtual disks to be used as source virtual disks for VSS snapshots must not have names longer than 16
characters. The VSS hardware provider uses the base virtual disk name as a prefix for the snapshot and
221