There was a lot written last week surrounding VMware's release of vSphere 4.1. Netapp appeared to have a lot to say, but it was confusing to figure out what they were really talking about. I think I've got it now.
It's unusual for a company to be invited as a centerpiece of high-visibility festivities and then mysteriously decide not to follow through. It would be like getting complimentary tickets and backstage passes from Lady Ga Ga herself, telling all your friends about it and then not going. It it does make one wonder. Why wouldn't you do whatever it takes to be included in VMware's big summer announcement party? Well, if you're Netapp, the answer appears to be - "Being there is over-rated. Just make sure everyone thinks you were." Call it Photoshop for PR or call it keeping your poker face, it's a mash up of a blown opportunity and opportunistic courage.
The excitement for VMware's storage partners was concentrated in two areas: VAAI (vStorage API for array integration) and SIOC (Storage I/O Control). The initial release of VAAI includes new SCSI block storage commands that allow the arrays to offload host systems from redundant, resource-consuming tasks. SIOC is a method for managing I/O queues to create more fairness in accessing storage resources. Netapp issued a press release last week in conjunction with the vSphere 4.1 release, but it was for their Virtual Storage Console, not for the support of the storage enhancements in vSPhere 4.1. There was a flag waving mention of VAAI:
"Additionally, NetApp is supporting the new VMware vStorage APIs for Array Integration (VAAI) capabilities that offload data management tasks from the host server to the storage system. This can free up host CPU cycles for better performance and increased virtual machine density."
That's not exactly saying anything, but its more than they had to say about SIOC, which was zilch.
The bottom of the release directs readers to Vaughn Stewart's blog for more info. Apparently, Netapp's PR department left the rest of the innuendo up to Vaughn - a diligent and loyal Netapp employee who understands that sometimes a vendor blogger doubles as a PR bagman. It looks like I need to add a new chapter to Vendor Blogging with Dummies.
You have to dig into the comments to get some of the details, but Vaughn's blog does a decent job explaining that Netapp is working on delivering VAAI functionality in Q4 2010. Now, that's not all that late considering its only 6 months or so away, but as a privileged insider to VAAI development, it's not a great showing either. In fact, it wouldn't surprise me if some of the companies who were not in the program, such as Compellent, HP, IBM and Xiotech come out with VAAI plug-ins before Netapp does. As for 3PAR, we will have our VAAI plug-in available in September as part of a maintenance release. We didn't have a lot of time to develop VAAI functionality after gaining access to the APIs in early 2010, but we fast-tracked the development of it in order to make the announcement.
As much as I admire Vaughn's hutzpah for stepping in to carry the load that others at Netapp should have, there were a few problems with what he said. First was the absurd statement that " SAN is attempting to be more NAS-like". There is so much wrong with that statement that it's difficult to find a place to start. Who or what is SAN? Is VMWare SAN? Is the T10 SCSI standards committee SAN? Is SAN the being an embodiment of SAN the block protocol? Is there a virtual reality thing going on here? And what is NAS-like anyway? Does it have anything to do with the size of one's beak or the way particular vowels resonate in the sinus cavities? Or is it like racing the back roads in a used chevy? Whatever Vaughn meant, I tend to dislike the imprecision of technology anthropomorphism.
The second thing Vaughn said was "As for the first release of VAAI... These features ALREADY EXIST in NFS." Really, block zeroing? That is a function developed for EagerZeroThick volumes, which are only supported on VMFS datastores, not NFS datastores. Perhaps we will see that change in the future, but for now its SAN only.
Hardware assisted locking is a way to allow smaller granular locking for VMFS and addresses an issue with VMDK-level operations in a shared datastore. Because NFS puts VMDKs in separate datastores, which are locked independently, hardware assisted locking is unnecessary for NFS. In other words, its a SAN only function because the current NFS datastore architecture doesn't need it.
The other API in VAAI is Full Copy. This VAAI API appears to be functionally equivalent to a Netapp utility called RCU (Rapid Cloning Utility) that was included as a function in their Virtual Storage Console. It is not, however, something that exists in NFS, unless Netapp wants to give that feature to all it's NAS competitors. As a vSphere function, Full Copy will be available to all vendors that implement the VAAI APIs. It will be interesting to see what differences there are as far as programmatic control using the VAAI plug-ins, vendor-specific consoles and Powershell.