Vernalex.com - Printer Friendly Version

Display Name (?):

MS Software Shadow Copy Provider

Short Name (?):

SwPrv

Executable (?):

dllhost.exe /Processid:{81B8F361-4F98-4D4E-B40B-88D81C3E6B8F}

Library (?):

None.

Depends On (?):

Remote Procedure Call (RPC)

Supports (?):

None.

Description (?):

Manages software-based volume shadow copies taken by the Volume Shadow Copy service. If this service is stopped, software-based volume shadow copies cannot be managed. If this service is disabled, any services that explicitly depend on it will fail to start.

OS (?):

XP Home/Professional, Vista Home/Business, Server 2003, Vista Server

Startup (?):

Default	Home	Workstation	Server	Minimal	Tweaked	Automatic
Manual	Manual	Automatic	Automatic	Disabled	Disabled	Disabled

Explanation (?):

The MS Software Shadow Copy Provider ({FD5398EF-1D09-46F4-9140-DA2A6B4F3AC7} through dllhost.exe) service provides organization to the shadow copy infrastructure. This component of Volume Shadow Copy (VSC) does not take the snapshot of the drive, but rather coordinates with the volume shadow copy service in a joint effort to make snapshots and to store them as requested. In other words, this service provides the way to view past changes, and it also is the service that the VSC speaks to save the snapshots.

Previous versions of Windows had no native method for performing a complete backup of files on a server. Nor was there the ability to revert files stored on a server to previous revisions. However, with Windows XP and Windows Server 2003 you can take advantage of the Volume Shadow Copy service. This component of Windows is able to take a complete backup of a server's data at boot, and then is able to modify the backup with changes (deltas) as time goes on. Although it should be noted that file changes are calculated on schedules. This means that it is possible for you to retrieve files that you have deleted, and it is possible to return to a previous version of a file, such as a document, if you were to make mistakes you did not like. From the server side the backups take up less space than expected because the original file is saved, along with the changes, instead of several copies of the same file.

This component of Windows also provides the ability for the server to backup files that are locked. This means that if you have a file open that the Windows server can, in the background, remove the file handle, backup the file, and then return the file handle to your workstation without you ever being the wiser. This means that there are no files skipped during the backup process. This means that administrators do not need to have formal backup times, as the backup could be performed at any time of day. However, this means that a replica of the file must be produced at the time of unlocking it, so the space to duplicate the file must be available on the server.

If you did not understand the above then you most likely do not need to worry about it. This service is only needed in a corporate environment where there are workstations and servers that need centralized backup. Normally this service would be used for fairly large infrastructures on a domain, but it could also be used for a small business. If you are using this service then you may want to set it to automatic. If you do not use this, like most people, then you should leave it set to manual as it is only started when needed.