I’d like to think I’ve visited a lot of customer sites over the years. Admittedly most of these are “enterprise” class with multi-terabyte if not petabyte quantities of storage. None of those customers have ever bothered deploying iSCSI as their storage protocol. Invariably block storage has been implemented using fibre channel and file using CFS or NFS. Somehow iSCSI just doesn’t seem to figure. I have a few thoughts on why…
- Network versus Storage. There’s no doubt, Network and Storage teams get on about as well as cats and dogs. Although both support networking technologies, they are implemented fundamentally differently. In fact the only organisation I’ve seen that had the Network team managing fibre channel had implemented it like an IP network and it was a mess. As the iSCSI protocol means handing control of the physical transport layer to the network team, then the simpler option is to avoid using iSCSI in the first place.
- It’s Too Easy. This may seem like a contradiction, but running a fibre channel network usually means managing a controlled environment. Nobody connects without permission, nobody gets access without being zoned in. Implementing iSCSI is simple and so inherently means less control.
- There are no Standards. Fibre channel networks are great because you have to use expensive components and match everything against approved matrices or you don’t get support. iSCSI can be implemented using the cheapest NIC and virtual iSCSI targets. However, this ease of use also means there’s no vendor certification in the way there is with fibre channel. Who are you going to blame when things go wrong?
- FCoE will Rule The World. Yes, Fibre Channel over Ethernet will be the One Storage Protocol to Rule Them All and replace fibre channel, iSCSI, AoE, NFS, CIFS, and any other protocol you care to name. OK, I’m being slightly sarcastic, but FCoE is set to harmonise the physical connect, leaving iSCSI redundant.
So what’s the future for iSCSI? We’ve seen the rise in popularity of home storage devices in recent years (think Iomega and Drobo). We’re now seeing these devices sporting Ethernet connectivity that supports iSCSI. With iSCSI Initiators (like the one in Windows) being totally ubiquitous, it’s a no-brainer to deploy iSCSI in home and small office environments. Maybe there is still a future for iSCSI after all in providing low-cost block storage for the consumer masses.