Administrator's Guide

This will make your cluster work quicker. Additionally, CSV enables Live Migration which allows
you to move a running VM from one node to another node with zero downtime. Since disk
ownership no longer needs to change when a VM moves to another node, this makes the process
quicker and safer, allowing clients to remain connected while the virtual machine is moved to
another node in the cluster. The CSV disk resource which is owned by a cluster node is called as
coordinate node. The VMs which are hosted on the CSV disk can be owned by either coordinated
node or any other node of the cluster. When a disk is in the available storage group, it can be
converted to CSV. When a CSV disk is created in the Failover Cluster, internally, a hidden role
will be created by the failover cluster which is not visible in the Failover Cluster GUI, but visible
through cluster.exe command output. Only CSV disk is shown in the Failover Cluster GUI. The
name of the CSV role is in the form of a GUID. For every highly available VM created on the CSV,
there will be a role created in the Failover Cluster which is independent of the CSV role. The
following screenshot has two virtual machines created on a single CSV Disk. For each virtual
machine there is a role created.
In a multi-site storage array replicated environment, CSV disks are replicated to the remote
datacenter using the array based remote replication feature. VMs residing in the CSV disk can run
on any cluster nodes (physical servers). In case of disaster to the primary datacenter, CSV disks
need to be brought online in the secondary datacenter. For this, storage failover needs to be done
after checking the CLX disaster recovery rules before cluster brings the CSV disk online. This is
where CLX comes into picture to swap replication direction and perform the storage failover in an
automated fashion to add failover capabilities for the CSV disks in the clustering environment.
3PAR Cluster Extension supports CSV disk on Windows Server 2012 in addition to non CSV disk
support. Configuration of CSV disk for CLX is similar to configuration of normal disk for CLX support.
Since the CSV role is hidden and not seen in Failover Cluster GUI, CLX has provided PowerShell
Cmdlets to configure Cluster Extension 3PAR resource for the CSV disk. See “Cluster Extension
Cmdlets for CSV and Virtual Machine Management” (page 58) on how to configure CSV disk for
CLX.
14 HP 3PAR Cluster Extension features