Understanding Microsoft VSS and Zadara VSS Hardware Provider
The Microsoft Volume Shadow-copy Service (VSS) is the storage management interface for Microsoft Windows Server Operating systems. VSS allows the Zadara VPSA Storage Array to interact with third-party applications that use VSS Application Programming Interface (API). Microsoft VSS is included in Windows Server 2003 and later Windows Server releases.
The Zadara VSS hardware provider is a Windows service. Microsoft's VSS attaches to the service and uses it to coordinate the creation of snapshot volumes on the storage array. VSS-initiated volume snapshots can be triggered through third-party backup tools known as "requesters".
As a result, the snapshots "taken" by the VSS service are application consistent.
Downloading Zadara's VSS hardware Provider
The installer for Zadara's VSS hardware providers publicly available and can be downloaded for both x86 & x64 systems:
Windows Server 64bit - ZadaraHardwareProvider_x64.msi
(MD5 Checksum: 022f84908bb4e24ee30e3f63e4035cd2)
Windows Server 32bit - ZadaraHardwareProvider_x86.msi
(MD5 Checksum: 1bfad2fc855fc26552c1bc2b4ab53437)
Zadara VSS Hardware Provider dependencies
- Microsoft Visual Studio 2012 redistributable package.
- SAN Policy = OnlineAll
This can be done by launching diskpart utility and invoking the command,
By default, SAN Policy will be set to OfflineShared. This policy will prevent the new volumes to be set to Online by default.
The VSS Re-sync LUN command, when executed, re-synchronizes the destination volume with the snapshot data and exposes the volume back to the host. If the SAN Policy is set to OfflineShared, then the volume when exposed after the re-sync operation, will not become Online and as a result, the Re-sync LUN Command might fail. Hence, the ensure that SAN Policy is set to OnlineAll.
Installing the Zadara VSS Hardware Provider
- Execute the MSI installer (ZadaraHardwareProvider_x64.msi or ZadaraHardwareProvider_x86.msi)
- Review and acept to EULA
- Accept or modify the installation location
- On the "Ready to install" dialog, click on "Install" to start the installation.
You may install the VSS Hardware Provider non-interactively from Command Prompt:
msiexec /quiet -i <Zadara VSS Hardware Provider msi file>
Zadara Registry Tool overview
The Zadara VSS Hardware Provider requires an Zadara VPSA IP and access key to connect to the VPSA and perform any action (like listing volume, creating snapshot etc).
The Zadara Registry Tool, a simple GUI application, provides an easy and intuitive approach to specify the VPSA IP and user's Access Key from and store it in the system registry.
The registry tool provides the option to add/modify/remove array configuration in to the System Registry. When a volume from a array is mapped to the host operating system, the administrator has to run this registry tool to add the array configuration to the system registry.
Without adding the array in the Registry tool, the hardware provider will not be able to access the corresponding Zadara VPSA and its volumes.
Logs will be written in "ZadaraVSSProvider.log" log file under "C:\ProgramData\Zadara\" directory.
The logs are managed by the provider, and will be rotated in case the log file size exceed the 5MB threshold (maximum of 5 log files will be preserved).
Fixes in current version
Zadara VSS Hardware Provider - GA 5 Release - Release Date 23 February 2017
- Updated the version number to 220.127.116.11
- Fix memory leaks in VSS provider.
Zadara VSS Hardware Provider - GA 4 Release - Release Date 29 June 2016
- Updated the version number to 18.104.22.168
- Call a new API create_snapshot_set when creating shadow copies
Zadara VSS Hardware Provider - GA 3 Release - Release Date 09 June 2016
- Updated the version number to 22.214.171.124
- Added a patch to the VSS Hardware provider that passes in the API call a longer timeout value of 30 sec (#8648).
Zadara VSS Hardware Provider - GA 2 Release - Release Date 24 Feb 2015
- Updated the code to work for the new version of VPSA having Product ID as VPSA. The VSS Hardware Provider will now work for both old and new version of Zadara VPSA.
- Updated the version number to 126.96.36.199
Zadara VSS Hardware Provider - GA Release - Release Date 28 Jan 2015
- Updated the version number to 188.8.131.52
- Added Zadara icon for the Zadara VSS Hardware Provider in the Add/Remove Programs.
- Added Zadara icon for the ZadaraRegTool
- Created a shortcut for ZadaraRegTool and placed in the start menu
- Updated installer to check, if any previous version of Zadara VSS Provider is installed
When re-syncing more than one snapshot volume to different destination LUN, whose size's are smaller than the size's of the corresponding volume's to which the snapshot belongs, the re-sync LUN command might just freeze without giving a output. But the destination LUN would have actually re-synced.
This behavior is observed randomly. In such cases, exiting the diskshadow application and relaunching it again should be fine to continue with other operations.