On N-Port ID Virtualization and VMFS datastores
Jul 27, 2009 Blogs
Today, I was preparing an environment for a physical relocation. My employer is moving to a new office building, and so the complete IT needs to be moved, too. We’re currently running all services (except a now defunct fax server and a Cisco CallManager) on four Dell PowerEdge 1950′s, attached through Fibre-Channel to a Dell/EMC CX3-10c SAN using Fibre Channel only.
Our regular backupsolution won’t allow for backup or recovery of complete VM’s, so to make sure no data gets lost, I wanted to create backups for disaster (say, the SAN hurls down a case of stairs by accident) recovery (I want my data back!) purposes. I’ve used and loved Veeam Backup and Replication for loads of other customers, so I wanted to give it a try in this scenario.
Installing and configuring the software was a breeze, and within thirty minutes, I was making backups of my VMDK’s. Veeam happily grabbed loads and loads of data, but it didn’t perform as I had hoped:
As I have installed Veeam in a virtual machine, I couldn’t leverage VMware VCB’s ability to access the SAN directly and backup using VCB’s SAN mode. Instead, I had to use NBD mode, which is a lot slower. But wait! Wasn’t there a way to attach VM’s to the fabric directly?
With NPIV, you can do just that! I powered the VM off, enabled NPIV, and booted it up again. While that was running, I checked the physical HBA’s, Fibre Channel switches and the CX3-10c for NPIV support. All was well, until I got to the point that the SAN didn’t recognize the newly created WWN. It simply did not show up…
After some Binging Googling, I found out that NPIV only works with RDM’s, not with direct access to the VMFS datastores. Mister Boche has written all about it here.
Bummer, that craps all over my plan to back up data with VCB’s SAN mode. Back(up) to square one…
July 27th, 2009 at 21:12
Of course it does not work with a VMFS volume. What the hell is a VM supposed to do with the VMFS volume itself?! Even if it would work it’s a huge risk.
July 27th, 2009 at 21:29
A VM should be able to do the same as a physical machine does with a VMFS volume: VCB. Why create a boundary between physical and virtual machines in this respect? VMware has been fighting to do 100% virtualization for years, why shouldn’t we be able to virtualize the backupserver?
July 28th, 2009 at 9:11
How many people do you think contact VMware on a daily base who connected their VCB proxy to their VMFS volume without disabling automount?
Anyway, this is NPIV 1.0 there’s more coming but for now this is a known limitation.
I just wonder why you aren’t leveraging the hot-add mode. Or is that a limitation of VEEAM?
July 28th, 2009 at 19:25
I would thought that it’s a good idea.. Usin a VM as a backup server as long as it’s gets support from the VCB to access the FC SAN directly. Shame it does not work…
Anyway, it was worth it to give it a try…