Cluster Shared Volumes (CSV) is the first Failover Clustering feature introduced in Windows Server 2008 R2 for use with Hyper-V roles. A Shared Volume Cluster is a shared disk containing a volume of NTFS or ReFS (ReFS: Windows Server 2012 R2 or later) that is made accessible for read and write operations by all nodes in Windows Server Failover Cluster.
Video Cluster Shared Volumes
Benefits
This allows complete mobility of virtual machines (VMs) across clusters because each node can access VHD files on a shared volume. Cluster Shared Volumes simplifies storage management by enabling a large number of VMs accessible from common shared disks. CSV also improves cluster resistance by having I/O error detection and recovery via an alternative communication path between the nodes in the cluster.
While CSV is not required for Live Migration of VMs, it reduces the potential termination period at the end of the migration because the NTFS file system does not have to be removed/installed just as with traditional disk clusters. This helps ensure immediate uninterrupted migration because the physical disk resources do not need to be moved between nodes. CSV increases the likelihood that direct migration will be completed within the TCP reset window and ensure seamless operation for the client.
Maps Cluster Shared Volumes
Requirements
To use CSV, Hyper-V VM is configured and an artificial virtual hard disk (s) is created or copied to a CSV disk. Some VHDs can be placed on a CSV which in turn is associated with multiple VMs that can run across different nodes within the cluster.
Technical Details
Cluster Shared Volumes operates by setting the metadata I/O operation between nodes in the cluster via the Server Message Block protocol. A node with LUN ownership that orchestrates updates of metadata to NTFS volumes is referred to as Coordinator Node. Read/write operations are forwarded directly to the Serial attached SCSI, iSCSI, Fiber Channel, or Fiber Channel over Ethernet shared storage via block protocol.
CSV builds a common global namespace across clusters using NTFS reparse points. The volume can be accessed under the% SystemDrive% \ ClusterStorage root directory of any node in the cluster.
The cluster will automatically prioritize the most profitable network to direct I/O operations by selecting a shared cluster network with the lowest cluster network metric values, this can also be configured manually. Public networks (i.e. networks connected to users) are assigned higher network cluster metric values ​​by default; it supports I/O operations from using public networks that may already be filled with user requests.
CSV can be enabled in the Failover Cluster MMC Manager snap-in by selecting 'Enable Shared Volumes' from the information panel after creating a cluster. In addition, CSV can be enabled using PowerShell:
Import-FailoverClusters Module (Get-Cluster [-Name & lt; cluster Name & gt;]). EnableSharedVolume = "Enabled"
References
External links
- Step by Step (Microsoft Clustering & HA Team): http://blogs.msdn.com/clustering/archive/2009/02/19/9433146.aspx
- Step by Step (in English): http://www.servercare.nl/Lists/Posts/Post.aspx?ID=89
- Explained: How CSV works (in German): http://www.server-talk.eu/2009/09/15/einblicke-in-cluster-shared-volume-csv/
- EMC Symmetrix with Hyper-V (in English): https://web.archive.org/web/20101011204459/http://www.emc.com/collateral/hardware/white-papers/h6643-symmetrix - microsoft-hyper-v-wp.pdf
- Best Practices for NetApp Storage (in English): http://www.netapp.com/us/library/technical-reports/tr-3702.html
Source of the article : Wikipedia
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