I have been thinking about why virtualization is now mature in lots of IT Infrastructure technologies…
- Servers (VMWare, Parallels, Mainframe VM, Solaris Domains, AIX LPARS etc..)
- Networks (Virtual Private Networks VPNs are endemic)
- Desktops (VDI)
…but it just hasn’t got to mainstream in enterprise storage.
I think that I have worked it out. Enterprise storage is (almost) the last vestige of proprietary computing where a small number of storage controller vendors jealously manipulate and control the market. What do I mean by manipulate and control the market? Well remember when certain mainframe vendors used Fear Uncertainty and Doubt (FUD) to control the mainframe market? Remember when buying plug compatible hardware was risky (or so your mainframe account manager would suggest)?
Well enterprise storage vendors play exactly the same game today. Try breaking up your enterprise storage solution so that you can get best value, say attempt to buy the Fiber Channel switches and SAN from Cisco and the Storage Controller from EMC. You will fall off at the first hurdle because you can’t buy Cisco SAN switches directly, they come via Storage Controller vendors. Even if you could, I can hear the FUD whispering campaign already.
“We can’t support those configurations, the storage architecture is so complex that we must deliver the entire end-to-end solution. You are taking a huge risk and if it goes wrong you are on your own….”
So when you make a decision to go with one enterprise storage vendor, it is extremely hard to break away from them. Unless you just throw all of the old stuff out and replace it with a completely new SAN and new Storage Controllers, it is impossibly hard to get end-to-end support for a mixed environment. So most firms don’t, they stick with their old vendor and allow prices to creep up and service to drop because the alternative is just too difficult.
The answer to this conundrum is with us. Take the intelligence out of the Storage Controller and put it into the network! Use virtualization to commoditize the storage controllers and introduce competition into enterprise storage.
Some years ago I worked at Cable & Wireless and implemented IBM’s SVC in order to commoditize enterprise storage and to deliver operational benefits.
Here are those benefits:
- Separation between the storage front end and back end allows data to be migrated transparently
- Ability to deploy low cost storage (SATA) for all applications and only migrate them to higher performance storage if the performance is unacceptable – we can migrate them transparently with no outage
- We can remove out of date or unreliable storage arrays with no down time
- We can increase the capacity of storage for a host without any down-time
- We can totally change the design of the back end without impacting the hosts
- (Yes you can screw up the initial design and then change it later)
- We can integrate multi vendor storage arrays with no host compatibility impact
- We can snapshot between FC and SATA disks allowing Integration and User Acceptance testing to be performed at low cost
- We can provide inter-site synchronous replication without expensive array based software such as SRDF