This post won't
explain NPIV as a standard and how it works. But we will see VMware
implementation for this technology. Its more or less similar to the
implementation in Cisco UCS & HP FlexConnect.
NPIV is a technology
used to allow multiple WWNs to register with SAN Fabric through single HBA and
claim multiple FCIDs.
In vSphere
environment, NPIV can be enabled per VM. Each VM will have vHBA which will have
WWNN/WWPN unique. Therefore multiple VMs each with vHBA can register with SAN
Fabric through single host HBA. This is the concept of NPIV.
WWNs are assigned to
VMs once you enable NPIV even if the VM is off. You can see those WWNs in VM vmx file.
wwn.node = "2807000c29000001"
wwn.port = "2807000c29000002"
wwn.type = "vc"
wwn.enabled = "TRUE"
However, vHBAs will
be created only once the VM is powered-on. They are called VPORTs and will own
the WWNs of the VM. Once the VM is powered-off, the VPORT will be destroyed.
So what's the advantage of NPIV?
Since each VM has
its vHBA with unique WWNs, VMs can connect directly to SAN using vHBAs
bypassing VMFS layer. Zoning/Masking in SAN Fabric should be done based in
vHBAs WWNs.
Also, very important
to note that the type of disks to be added to VMs should be RDMs since we are
bypassing VMFS layer. You can still add VMDK disks but those won't be taking
the advantage of NPIV.
In this case why we need NPIV? Why not to use RDM
disks directly without NPIV?
The advantage of
NPIV is having Granular Control. Without
NPIV, zoning/masking in SAN fabric is done based on host's HBA WWN. This means
that all VMs hosted on top of this host will have visibility to all LUNs as RDM
disks which is let's say less secured especially in multitenant environment.
With NPIV, you are
extending SAN zoning to the VMs which one step beyond to control LUNs presence.
You can present LUN-A to VM-A which won't be visible by VM-B when trying to add
RDM disk. This is using VM-A WWNs.
Limitations & Requirements
1. Host HBAs and FC Fabric
should support NPIV
2. NPIV supports vMotion and
will retain same WWNs. If destination host doesn't support NPIV, physical
HBA WWN will be used to connect VM to LUN (assuming proper zoning is
done).
3. NPIV doesn't support Storage
vMotion
4. Cloning a VM with NPIV
enabled doesn't retain WWNs.
How to Configure?
1. Edit Settings of your VM
2. Navigate to Options Tab > Advanced > Fiber Channel NPIV.
3. Enable NPIV as below snapshot. NPIV can be enabled only for powered-off VMs.
Thanks Good one... :-)
ReplyDeleteIt is possible to create snapshot on vm with npiv, becouse of the backup system we hav (EMC avamar) need snapshot.
ReplyDelete