Contemplating IT

We did research on IT professionals and their major priorities over the last 18 months and all of them emphatically stated that implementing VMware was one of their top initiatives significantly driving down costs and improving operations. These IT professionals also said, however, the biggest challenge they faced with their VMware environments is network storage. Dedicated storage managers are buried under a mountain of projects and day-to-day operations that consume so much of their time that taking on new tasks is nearly impossible.

Another important dynamic we’ve observed is that VMware administrators are finding themselves becoming quasi-storage administrators, which is somewhat akin to asking a brain surgeon to operate on the heart. This is not due simply to the inherent complexity of most networked storage systems; it is an issue of specialization as well.

Ironically NFS, the protocol of geeks, is a means to simplify VMware and networked storage. It turns out there are a number of customers using NFS with VMware and as a result they have eliminated much of the day-to-day complexity of managing network storage with VMware. The following are the advantages of using NFS with VMware versus FC and iSCSI SAN approaches:

• It’s very simple to add NFS datastores. With NFS there is no LUN management. This simplicity addresses configuration issues that might come back to bite you in a SAN environment. The storage provisioning process for SANs often requires a dozen or more time-consuming steps. Missing any step may result in disaster and you might not know it until it happens.

• You don't have to deal with all of the complexity of Fibre Channel, WWNs, zones, ISLs, etc.

• You can easily increase or more importantly decrease the size of NFS datastores online for capacity reclamation.

• Since you are using NFS you don't have to deal with VMFS or RDMs. This means you can have volumes bigger than 2 TB. NetApp supports a 16 TB file system; Isilon and BlueArc can support 100s of TBs in a datastore (and theoretically more).

• There is no single disk I/O queue with NFS, which means that performance is dependent on network bandwidth and the storage system itself. It also means that NFS performance can keep up with even FC in VMware environments.

• You can backup whole VMs, or files within VMs.

• Restoration of VMs is flexible including individual VMs, multiple VMs or files within VMs.

• The cost of FC is higher including the equipment and support. This is an argument for both NFS and iSCSI over FC.

• One customer pointed out that the tools to troubleshoot IP networks are much better than FC, another advantage for both NFS and iSCSI.

• SAN expertise is more specialized than IP – it is harder to find the experts and to retain them (and they usually paid more).

The problem is there aren’t many vendors that offer storage systems that support NFS. There are literally dozens of SAN-based storage systems but only a handful of NFS or NAS storage systems in the market. Customers want choices and the fewer there are the less likely they will go down a particular path. And there are good reasons since competition fosters innovation, cost effectiveness and better service.

NFS for VMware has the potential of changing the storage landscape, but sadly, it probably won’t. The reasons are: it is a major challenge to educate the market; there is an enormous amount of incumbent SAN storage systems; and there is no one taking up the mantle to fight this good fight. Even NetApp has lost its fervor for NFS and has instead taken a “we provide whatever protocol you want” attitude, responding to the market versus driving it. That isn’t to say that NetApp isn’t promoting the use of NFS with VMware but it is not a core strategy and is only one of many things they talk about. BlueArc and Isilon are now focusing on NFS for VMware but they don’t have the same level of awareness or resources as the big storage vendors. However, if NFS for VMware is going to take off, these two vendors are in a position to sow some seeds and reap the rewards.

NFS is a more highly virtualized protocol than FC and even iSCSI. As a result it works much more easily and efficiently with VMware. If NFS is to become the dominant VMware protocol it is probably not the storage specialists that will make this happen but rather the VMware administrators who want highly virtualized networked storage without having to be a storage expert. The implications of this are significant as VMware continues to proliferate and those that manage these environments influence and decide what they need to be successful.