What is Hyper-V cluster shared volume
Cluster Shared Volume (CSV) is a feature of failover cluster. It is first introduced in Windows Server 2008 R2 and used with Hyper-V roles. Hyper-V cluster requires shared storage to provides access to all nodes in Windows Server failover cluster to read and write operations. A cluster shared volume is a shared disk that contains an NTFS or ReFS (ReFS: Windows Server 2012 R2 or later) volume.
Cluster shared volume (CSV) increases virtual machines (VMs) mobility in the cluster since any node can access VHD files on the shared volume. CSV facilitates storage management by allowing a large number of VMs to be accessed off a common shared disk. At the same time, it also improves the resiliency by performing I/O failure detection and recovery on alternate communication paths between nodes in the cluster.
How to configure Hyper-V cluster shared volume
Hyper-V Cluster Shared Volume is beneficial to VM failover and High Available VM. Before configuring Hyper-V shared volume, you should add an iSCSI LUN to a Hyper-V host and deploy shared virtual hard disk for Hyper-V shared storage.
Step 1. Create Hyper-V shared virtual hard disk
1. In Hyper-V Manager, right click the VM and select Settings.
2. Click SCSI Controller >> Hard Drive >> Add to start creating a new virtual disk.
3. On the Choose Disk Format page, select disk format as VHDX. Click Next.
4. Select disk type as Dynamic Expanding that will expand the disk size according to your need especially in production environment.
5. On Specify Name and Location page, click Browse to find the shared storage location (Cluster Shared Volume). Then select folder.
6. Configure the size of virtual machine. Then review the settings and click Finish.
7. Click the newly Hard Drive in SCSI Controller and click Advanced Features >> Enable virtual hard disk sharing.
Now you have created Hyper-V shard virtual disk that can be added into the CSV to achieve Hyper-V shared storage.
Step 2. Configure Hyper-V cluster shard volume
1. Navigate to Hyper-V Failover Cluster Manager. Click Storage >> Disk >> Add Disk.
2. Select the disk you want to add, and click OK.
3. Right-click the cluster disk and select Add to Cluster Shared Volumes.
You can notice the Cluster Shared Volume under Assigned to that proves you have successfully added a cluster to a shared volume.
Store VMs into the Hyper-V shared volume
In older to achieve high availability in cluster, you can use the CSV as a default location to store your virtual machines by changing the Hyper-V settings.
1. Access to Hyper-V Settings in Hyper-V Manager.
2. Select Virtual Hard Disks, and specify the default folder to store virtual machines.
How to extend Hyper-V cluster shared volume
When running enterprise systems, you often need to expand LUNs. In most cases, you can simply add the physical drive to the array and then use disk management to expand the drive to contain the newly expanded volume.
Unfortunately, for high available systems that run failover clusters and CSV, the drive cannot be managed by Disk Management. The following steps are feasible to extend CSV without downtime.
Procedure of Hyper-V extend cluster shared volume:
1. Expand the size of the LUN or disk in OEM SAN Management Software.
2. Open the Microsoft Failover Cluster Manager and check the CSV coordinator for the disk or LUN you have expanded.
3. Login to the CSV coordinator machine
4. If you are using the GUI version you can use the Disk Management under Storage in the Server Manager. You can now rescan for disks and then expand the Disk or LUN.
5. If you are using Hyper-V or Windows Server Core you can use diskpart
• First open diskpart.exe utility and start the cmd.
• Type diskpart, then press Enter.
• Type list volume to check all the volumes. Enter
• Type select volume. Enter.
• Type extend to increase the size of the selected volume. Enter.
• Type exit, then press Enter to exit the command prompt.
If there is not enough usable space on the specified disks to extend the volume, it’s recommended you to create a new one or move virtual machines.
How to protect virtual machines in Cluster
Although CSV provides advantages on VM management and shared storage, it has many limitations on network, compatibility and system and so on. The procedures of configuring Hyper-V shared storage are complicated and require extra cost on hardware.
For some enterprise, backing up virtual machines directly seems to be practical and affordable. So, you can try a third-party tool that allows you automatically back up VMs to a shared network location and provides instant recovery remotely. Here, I will use AOMEI Cyber Backup to demonstrate the detailed procedures.
AOMEI Cyber Backup is professional and convenient to back up multiple virtual machines to a shared location through the central console, and it is easy to restore VMs to different destination without any complex setting. It simplifies the VM management and reduces extra costs.
*You can choose to install this VM backup software on either Windows or Linux system.
Steps to back up VMs to a shared network
1. Access to AOMEI Cyber Backup and click Backup Task to create a new task.
→ Name & Device: type a name for backup task and select one or more virtual machines you want to back up.
→ Target: specify the location to store the backup files such as local or network path. It allows you to access the VMs conveniently.
→ Schedule: select flexible strategies and specify the time to run it automatically.
→ Backup Cleanup: select the retention polices to delete the unwanted backup files to save storage.
→ Click Start Backup.
3. Backup to the main screen and click Restore >> Restore to new location. If the original host has been damaged, it allows you to restore the virtual machines to different host with a few clicks.
With AOMEI Cyber Backup, it is affordable and efficient to back up unlimited virtual machines and achieves offsite storage and instant VM recovery.
Hyper-V cluster shared volumes simplify the storage management of virtual machine and allow shared storage for virtual machines in cluster. And configuring CSV also contributes to live migration in Hyper-V.