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Figure 3. Creating a new volume
It is a best practice to create a unique iSCSI volume for each VM in an SR. Thus, HP suggests
matching the name of the VM to that of the XenServer SR and of the volume created in the CMC.
Using this convention, it is always clear which VM is related to which storage allocation.
This example is based on a 10GB Windows XP SP2 VM. The name of the iSCSI volume – XPSP2-01 –
is repeated when creating the SR as well as the VM.
The assignment of Servers will define which iSCSI Initiators (XenServer Hosts) are allowed to
read/write to the storage and will be discussed later in the Configuring a XenServer Host section.
Configuring the new volume
Network RAID (2-Way replication) is selected to enhance storage availability; now, the cluster can
survive at most one non-adjacent node failure.
Note
The more nodes there are in a cluster, the more nodes can fail without
XenServer hosts losing access to data.
Thin Provisioning has also been selected to maximize data efficiency in the SAN–only data that is
actually written to the volume that can occupy space. In functionality, this is equivalent to a sparse
XenServer virtual hard drive (VHD); however, it is implemented efficiently in the storage with no
limitation on the type of volume connected within XenServer.
Figure 4 shows how to configure Thin Provisioning.
