What must be enabled for the volume shadow copy service (vss) to function?

With AWS Backup, you can back up and restore VSS (Volume Shadow Copy Service)-enabled Windows applications running on Amazon EC2 instances. If the application has VSS writer registered with Windows VSS, then AWS Backup creates a snapshot that will be consistent for that application. You can perform consistent restores, while using the same managed backup service that is used to protect other AWS resources. With application-consistent Windows backups on EC2, you get the same consistency settings and application awareness as traditional backup tools.

AWS Backup currently only supports application-consistent backups of resources running on Amazon EC2. Not all instance types or applications are supported for Windows VSS backups.

For more information, see Creating a VSS Application-Consistent Snapshot in the Amazon EC2 User Guide for Windows Instances.

To back up and restore VSS-enabled Windows resources running Amazon EC2, follow these steps:

  • Complete the required prerequisite tasks. For instructions, see Before You Begin in the Amazon EC2 User Guide for Windows Instances.

  • Download, install, and configure the VSS agent in AWS Systems Manager. This step is required. For instructions, see in the AWS Systems Manager User Guide.

  • Add an IAM policy to the IAM role and attach the role to the Amazon EC2 instance before you take the Windows VSS (Volume Shadow Copy Service) backup. For instructions, see in the Amazon EC2 User Guide for Windows Instances. For an example of the IAM policy, see .

  • Enable VSS in AWS Backup.

    To enable Windows VSS backup in AWS Backup

    1. Open the AWS Backup console at https://console.aws.amazon.com/backup.

    2. On the dashboard, choose the type of backup you want to create, either Create an on-demand backup or Manage Backup plans. Provide the information needed for your backup type.

    3. When you're assigning resources, choose EC2. Windows VSS backup is currently supported for EC2 instances only.

    4. In the Advanced settings section, choose Windows VSS. This enables you to take application-consistent Windows VSS backups.

    5. Create your backup.

Unsupported Amazon EC2 instances

The following Amazon EC2 instance types are not supported for VSS-enabled Windows backups because they are small instances and might not take the backup successfully.

Snapshots have two primary purposes: they allow the creation of consistent backups of a volume, ensuring that the contents cannot change while the backup is being made; and they avoid problems with file locking. By creating a read-only copy of the volume, backup programs are able to access every file without interfering with other programs writing to those same files.

What is a VSS Provider?

The data copy process can be handled by the file system or by specialized hardware; in the latter case a hardware VSS provider abstracts the functionality to the operating system. Applications can provide specific support for VSS through VSS writers which control how data is set to a consistent state at the beginning of a VSS operation and maintain that consistency throughout the process, among other functions.

Through the integration between the Volume Shadow Copy Service, hardware or software VSS providers, application level writers and backup applications, VSS enables integral backups that are point in time and application level consistent without the backup tool having knowledge about the internals of each application. For example, in a virtualization product such as Virtual Server 2005 R2 SP1 or Hyper-V in Windows Server 2008, a whole backup of an environment including several virtual machines can be created in a single operation, and the backups produced for the different VSS compatible guests in the system are transactionally consistent at the guest application level and point in time consistent among the different VMs, without the need for the guests to have backup agents installed. Windows software and services that support VSS include Windows Backup, Hyper-V, Virtual Server, Active Directory, SQL Server, Exchange Server, and SharePoint.

Enter the Pure Storage FlashArray VSS Hardware Provider

The Pure Storage VSS extension allows users to take volume snapshots while applications continue writing to the FlashArrays.Once taken, the snapshots are saved to the Pure Storage FlashArray. Note: The VSS hardware provider provides a REST API between the third party backup application and the Purity array. For more information about the REST API, refer to the Pure Storage REST API Guide. To use the VSS extension, you must install the Pure Storage VSS hardware provider on the Windows host machine (also known as initiator).

Release Information

What is the current released version of Pure Storage VSS Provider?

See our Volume Shadow Copy Service (VSS) Hardware Provider page for information on the latest release.

Which version of RestAPI is supported by the current released version of Pure Storage VSS Provider?

Pure Storage VSS Provider version 1.0.0 and version 1.0.1 supports FlashArrays with REST API 1.1. Any FlashArray that supports REST 1.1 will work just fine with this provider. For example, 3.4.3, 4.0.x, 4.1.x...etc.

NOTE: For Purity version 4.1.1 and 4.1.2 you MUST use VSS 1.0.1 as VSS 1.0.0 will NOT WORK! Please see below for more details...

VSS 1.0.1 should work with all versions of Purity starting with 3.4.3+

Release Compatibility

  • This release supports Windows Server 2012, 2012 R2, 2016, and 2019.
  • This release does not support Windows Server 2008 R2 or Windows Server 2008. Installations are allowed, but not currently supported.

How to Verify that You Have Pure Storage VSS Provider Installed

  • Check that it shows under Add/Remove Programs Control Panel
    What must be enabled for the volume shadow copy service (vss) to function?
  • Check Registry. Provider installs the following key: HKEY_LOCAL_MACHINE\SOFTWARE\PureStorage\VSS\Provider 
    What must be enabled for the volume shadow copy service (vss) to function?
  • From a command window (console window). Run the following command:
  • vssadmin list providers
  • Result should contain something like this:
    Provider name: 'Pure Storage VSS Hardware Provider (64-bit)'
     Provider type: Hardware
     Provider Id: {781c006a-5829-4a25-81e3-d5e43bd005ab}
     Version: 1.7.0

Verifying the User Privileges

Verify that you have Pure Storage system administrator rights to install the VSS hardware provider on the Windows host machine.

Verifying VSS Provider Service is Running

To verify that our VSS provider is up and running, so it can create snapshots, run Services MMC (services.msc from console window) and look for Pure VSS Provider service. When you click on it, you can verify if the service is currently started or stopped. Here is an example sceenshot of our VSS provider in stopped state:

What must be enabled for the volume shadow copy service (vss) to function?
  

To start the provide, simply click Start button.

Unattended Install / Uninstall

VSS Installer can be run silently without showing any UI or prompting the user. You must run the installer as administrator to avoid a case where Windows UAC my prompt the user for permissions to run, which can block script execution.

To run installer in silent mode, simply add /s to the installer command-line:

PureVSSInstaller.exe /s

Similarly, we can perform silent uninstall:

PureVSSInstaller.exe /x /s

This will use the default install location, which is %ProgramFiles%\Pure\VSS\Provider

Known Issues

Creating a Pure Storage VSS Hardware Provider snapshot on Windows 2008 generates multiple warning events.

When the Pure Storage VSS Hardware Provider successfully creates a snapshot, the process generates multiple warning events in the Windows Log - Application view of the Windows Server 2008 Event Viewer.

Here is a sample of the details that appear in the warning event:

Volume Shadow Copy Warning: The provider has reported a storage identifier that is not supported by VSS. Codeset:1, Type:4, Size:4, NextOffset:24, Association:1

This identifier will be skipped by VSS.

The warning events, which only occur on Windows Server 2008, are not related to the Pure Storage VSS Hardware Provider and can be ignored. Refer to the following Microsoft KB support article for more information: http://support.microsoft.com/kb/951793

Workaround: No workaround available.

  • Reinstalling the Pure Storage VSS Hardware Provider may fail. If you uninstall and then reinstall the Pure Storage VSS Hardware Provider, and the installer hangs or an error message pop-up window appears, reboot the system and then perform the installation again.
  • This release does not support the replication of snapshots created by the VSS Hardware Provider.
  • VSS 1.0.0 will fail to connect / authenticate with Purity version 4.1.1 and 4.1.2

4.1.1 and 4.1.2 of Purity have introduced REST API change that requires userAgent as part of the REST call, which prevents VSS 1.0.0 from connecting and/or authenticating with these versions. As a result, you cannot use VSS 1.0.0 with either of these two versions. You will need to download and use VSS 1.0.1 instead.


Importing Snapshots

Importing a snapshot set requires valid connections from the hosts to the Pure FlashArray. In VSS HW provider 1.1 and below this operation may seem to succeed, but starting in VSS HW provider 1.6 this operation will fail as intended.

Troubleshooting

Locating Log Files

 Log files are located under:

%PROGRAMDATA%\PureStorage\

 Provider service log files:

  • PureVSSHardwareProvider.log

Collecting Verbose Logging Info

Before collecting the log files, make sure to turn the verbosity level high (recommended level 4 for troubleshooting).

Valid log levels are 0 through 4 where 0 means errors only and 4 is verbose (tracing)

How to Change Log Levels?

Run the following command from the console window:

PureProviderConfig.exe log --enable --loglevel 4

The output will be something like the following:

Log Enabled
Log Level: 4 [TRACE]

Listing FlashArrays registered with VSS Provider

For the VSS Provider to function properly and start creating snapshots, it requires at least one FlashArray to be registered with it. To list all registered FlashArrays, run the following command:

How does VSS shadow copy work?

A shadow copy is a snapshot of a volume that duplicates all of the data that is held on that volume at one well-defined instant in time. VSS identifies each shadow copy by a persistent GUID. A shadow copy set is a collection of shadow copies of various volumes all taken at the same time.

Is VSS enabled by default?

Microsoft Volume Shadow Service must be enabled in the OS (it is enabled by default) The system must have an NTFS partition that exists on an internal drive, with at least 100MB of free space for the shadow copies.

What feature does the volume shadow copy service provide in the Exchange server?

The Volume Shadow Copy Service flushes the file system buffers and then freezes the file system, which ensures that the file system metadata is recorded correctly and the data to be shadow-copied is written in a consistent order. The Volume Shadow Copy Service tells the provider to create the shadow copy.

What is the function of VSS in backups?

A Volume Shadow Copy Service-based backup (VSS-based backup) is a Windows service that captures and creates snapshots called shadow copies. VSS, also known as Volume Snapshot Service, operates at the block level of the file system and enables virtual server backup in Microsoft environments.