The Quick Recovery Agent can be implemented
in conjunction with the VSS Enabler on Windows iDataAgents that
support VSS to conduct backup operations using a VSS Hardware
Provider. The Quick Recovery Agent uses the snapshot to back up large amounts of data without using
production server resources. Because the backup does not occur on the production
server, resources on the production server are not affected by this operation.
VSS Software Providers
Microsoft Volume Shadow Service is the default, and only supported VSS
software provider. The VSS software provider takes a snapshot of the source
volume, database or file, which is then used to create backups or QR Volumes
(when used with the Quick Recovery Agent).
Additionally, snapshots can be created with the software provider independently
of QR Volume creation (i.e., a snapshot is taken without creating a QR Volume).
These snapshots can be mounted, unmounted, and deleted from the QR Browse window.
VSS Hardware Providers
VSS Hardware providers allow you to create shadows without imposing a load on the
local client, or production server. For the purposes of VSS, the snapshot is
referred to as a shadow. Furthermore, an option to make the shadow
transportable has been provided, which allows you to mount, or import, the
shadow on another client. If a shadow is not marked as transportable, you will
not be able to mount the shadow.
When using VSS, the system will use the default provider to create the
shadow. If you have installed a hardware provider, this becomes the
default provider (VSS will use the hardware provider in place of Microsoft
Shadow Copy. The Microsoft Software Shadow Copy provider cannot be used for
snapshots if you have a VSS hardware provider installed. The VSS hardware
provider will have a higher precedence than the Microsoft Software Shadow Copy
provider and so QR Volume creation or backups with the Shadow Copy Provider will fail.
If there are multiple hardware providers residing on the same
machine, note that not all hardware providers will support the same volumes. For
example, the EMC provider will only support disks on the CLARiiON, the HDS
provider will only support HDS disks, etc. VSS determines if a supports the
volume to be snapped.
Install the Quick Recovery Agent and the VSS Enabler on the Source of the
snapshot. Note that you can de-select QSnap if you will be using VSS exclusively.
See Deployment - Quick Recovery Agent
for installation instructions.
Configure a QR Policy for VSS by selecting VSS as the Snapshot Engine
Type. For more information see QR
Policies.
For Microsoft Shadow Copy, specify the location of shadow storage from a
command prompt or through Windows Explorer. To do this from the command
prompt, run vssadmin add shadowstorage /For=<drive
letter1>: /On=<drive letter2>: where
drive letter1 is the
volume being snapped, and drive letter2
is any drive not being used as a QR destination volume.
VSS Hardware Provider
Install the Quick Recovery Agent and the VSS Enabler on the Source and Destination
hosts for the transportable shadow. Note that you can de-select QSnap if you
will be using VSS exclusively. See Deployment
- Quick Recovery Agent for installation instructions.
Configure a QR Policy for VSS Hardware shadows by selecting VSS as
the Snapshot Engine Type. The Enable QR Volume Creation checkbox should
be de-selected on the QR Policy. For more information see
QR Policies.
Your hardware provider may require some configuration before use. This may
include creating a cache LUN, setting up snap or clone groups, etc. Consult
your hardware provider for any necessary steps to set up a snap environment.
Only volumes that are owned by the hardware provider should be included
as subclient content.
VSS shadows taken together are treated as a single unit. Actions taken
on one shadow in a subclient will be applied to all shadows in the subclient.
(e.g., if shadows are created for the F:
drive and the G: drive through a single
subclient, and one of the shadows is imported, then the other will also
be imported automatically).
Before using VSS, review the following information:
Software Providers
If you are creating local QR volumes using VSS (Microsoft's Shadow copy,
not a hardware provider) you may need to change the VSS default cache storage
location. By default, VSS will store its snap cache in what it deems to be the
most efficient and appropriate volume. If this volume is also your QR destination
volume, we will not be able to exclusively lock said volume in a copy operation.
When using the Quick Recovery Agent with VSS, if a subclient contains multiple
volumes and a snapshot for one volume is deleted, then the snapshots for other
volumes are deleted as well. For instance, if snapshots are created of the F:drive
and the G:drive, and one of them is deleted in QR Browse, then the other will
be automatically deleted.
If you intend to manually delete snapshots, then
be sure to include the snapshots in their own individual subclients.
The Recover option is not applicable to VSS snapshots; however,
snapshots can be imported and mounted.
Hardware Providers
Windows 2003 service pack 1 is required to be installed on both source and
destination machine.
VSS hardware providers create snapshots at the LUN level, not the partition
level. It is recommended that each LUN have only one partition. Using LUNs with
multiple partitions may create unexpected results.
Transportable shadows can only be deleted after they have been imported.
If you attempt to delete a transportable shadow that has not been imported,
it will be automatically imported to the default import host before deletion.
You can create a VSS clone by creating the
nUsePlexMode
registry key and setting the DWORD value to 1. See your hardware provider
for setting up the environment. Currently, ProxyHost and the QR Agent support
clones using the EMC VSS CLARiiON provider.
The Recover option is available only to VSS hardware providers that
create non-transportable shadows.
The Make shadow transportable option in the QR Volume Creation
dialog specifies that the VSS hardware snapshot will be transportable. The
shadow must be transportable if you want to import it. See
Create a VSS
Transportable Shadow for procedures.
The Import Shadow option in the QR Volume Creation dialog
specifies that the VSS hardware snapshot will be imported to, and mounted on
the selected host. You can specify a destination for the shadow to be
imported through use of the Source-Destination Map button. See
Create and Mount a VSS Hardware Shadow in One Procedure.
A VSS shadow can be made writable in one of three ways:
To perform a data protection operation using this Agent a specific
Product License must be available in the CommServe® Server.
Review general license requirements included in
License Administration. Also,
View All Licenses provides step-by-step
instructions on how to view the license information.
Enabler Licenses
VSS Hardware snapshot also requires a license for the VSS Enabler.