HP Integrity VM 4.3 N-Port ID Virtualization - A brief overview

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Benefits of NPIV
This chapter lists few benefits of attaching storage through NPIV:
• Storage Isolation
With legacy shared (AVIO) storage, it is required that the host has access to all the storage that will be presented
to the VMs. With NPIV, the targets and LUNs are discovered by the VM directly as soon as a vHBA is created.
These LUNs need not be accessible or even visible to the host.
In a non-virtual environment, when a LUN is presented to a system, its access can be controlled by LUN masking at
the array or zoning on the SAN—both are based on the unique WWN associated with the physical HBA on the
system. The same can be achieved with NPIV HBAs when the storage or SAN administrator uses LUN masking or
zoning to restrict access—these actions can be done based on the virtual WWN (vWWN) associated with the
vHBA. This allows for storage isolation between the VMs and the host, even when they are sharing the same
physical HBA.
Storage isolation also provides:
– Security
The NPIV LUNs assigned to the VM are visible only to it. There is no risk of an application on the host or another
virtual environment accessing or overwriting the contents on these devices.
– Ease of storage provisioning
NPIV storage presentation doesn’t have to be a two-step process (first presenting the LUNs to the host and then
assigning each one to the VMs). This differentiates it from legacy AVIO storage.
With vHBAs, storage provisioning for a VM is the same as for a standalone system.
– Traceability of storage to VMs
With legacy AVIO devices, the VMs use storage that is either internal to the host or connected to the host over
the SAN. Since all the I/Os from the VMs and the host share the same physical HBA, the existing tools for SAN
diagnostics and usage monitoring do not have VM or application-level traceability.
This is not the case with NPIV. Here, there is a dedicated virtual connection between the VMs and the SAN
storage they use.
• Support for applications that need un-virtualized visibility to storage devices
There are many applications—such as Clustering, Symantec Storage Foundation (Enclosure Based Naming and
DMP), and SAN and storage management applications that cannot operate with a virtualized view of storage.
With NPIV, the VM operating system and applications have un-virtualized access to the LUNs discovered behind
the vHBA, thus enabling a host of applications.
There are some management applications like HP Replication Solutions Manager and HP Storage Essentials that
have a dependency on Storage Networking Industry Association (SNIA) API support, in addition to un-virtualized
access to the storage. SNIA support for NPIV LUNs is provided.
• Quality of Service
With NPIV, applications running in the VMs can have service-level agreements assigned to them, and the host and
the VM drivers help ensure that these are honored by propagating them down the stack.
HP QoS is available with the HP XP24000 Disk Array. For more information about the array, please see
www.hp.com/go/xp24000.
• SAN and storage chargeback
Since NPIV allows each VM to have its own dedicated access to the set of storage assigned to it, SAN and storage
chargeback software can track the resources used by the VM using the WWN associated with the vHBAs.
• Easier migration
HP Integrity VM supports online migration from one host to another. Prior to attempting an online migration, the
SAN/storage administrator has to ensure that the target host also has access to the required backing stores. With
NPIV, online migration is easier because the vHBA and its vWWN moves with the VM to the new host. The storage
and SAN administrator need to only ensure that there is SAN connectivity between the target host and the storage
devices for online migrations to work seamlessly.