Server User Manual

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Network RAID across the cluster of storage nodes.
XenServer host machines also deliver a range of high-availability features, including:
Resource pools of XenServer hosts
Multiple network interfaces bonded together
The use of external, shared storage by VMs
VMs configured for high availability
To help eliminate SPOFs from the infrastructure, network links configured as bonded pairs can be
connected to separate physical switches.
In order to survive a site failure, XenServer resource pools can be configured as a stretch cluster
across multiple sites, with HP StorageWorks P4000 SANs maintaining multi-site, synchronously-
replicated SAN volumes that can be accessed at these same sites.
Enhancing infrastructure availability
The infrastructure that has been configured in earlier sections of this white paper (shown in Figure 24)
has an SPOF the network switch. By adding a second physical switch and connecting each bonded
interface to each switch, as shown in Figure 25, this SPOF can be removed by adding a network
switch.
Implementing switch redundancy for the LAN and SAN increases the resiliency of both VMs and
applications.