Compellent storage grid is on its way
About this Live Volume thingamyjiggery
Compellent is also introducing its Live Volume technology with this release, as a software-only upgrade and supporting all Storage Center models and configurations. Live Volume asynchronously replicates a stored volume of data to a second Storage Center array, either in the same datacentre or on the same campus. It is now available on general release after a testing period. Bob Fine said: "We announced our vision for Live Volume 18-20 months ago and provided early code to a small group of customers this spring. We have been continually testing and enhancing it since, based on customer feedback."
Live Volume is analogous to VMware's vMotion and with it an application in a virtual machine can move from one physical server to another (or one virtual server to another) and the storage associated with it – the volume – moves as well, with no loss of storage access. This works with any O/S virtualisation software and aids in hardware migration and planned outages. If this sounds familiar it is probably because it is similar to a capability Brocade offers with its recently-announced VDX switch.
Compellent states Live Volume is a virtualised storage application that provides non-disruptive storage migration between SANs in an integrated environment. Live Volume enables on‑demand volume migration, zero downtime maintenance and disaster avoidance capabilities at a fraction of the price of EMC’s VPLEX, it claims, and requires no hardware, no outages and no system reconfigurations. Different storage volumes can be replicated to different Compellent arrays in a grid-like set-up. The technology is optimised for campus migration "at this time".
Fine said: "Live Volume supports any network connectivity protocol such as 10GbiSCSI, FCoE, iSCSI and FC, and customers can use Live Volume with any tier of storage that is supported by the Storage Center 5.4 hardware as well as previous generations of hardware. It supports any virtualisation environment from VMware, Microsoft, Citrix and Oracle." The marketing manager continued: "Live Volume will make it easier for companies to scale out and move data between systems on demand for dynamic business continuity. Over time, we will continue to make further product enhancements that will allow us to further penetrate the enterprise market."
Live Volume will place an extra processing burden on the controller. Storage consultant Chris Evans said: "With Live Volume, as a LUN is moved, the new target array has to both serve data and move data to the new location. This put significant extra load on the new target. I don't know how many arrays can be in Live Volume, but I would imagine the intention from Compellent would be to have a many to many relationship. If that's the case then I can see a lot of that extra [controller] horsepower being taken up moving data between arrays and handling I/O for non-local data."
The enterprise market: direct or indirect?
The Storage Center 5.4 product seems to have more processing power than it needs and Compellent is making noises about grid storage for the future. Does this mean Compellent is focussing more on the enterprise market?
Stifel Nicolaus analyst Aaron Rakers said: "I believe Compellent will continue to play more into the midrange market than high-end" (eg, against EMC’s Symmetrix, HDS’s VSP, IBM's DS8700, etc). His view is characteristic of one that thinks a direct sales approach, coupled with a strong services offering, is important in enterprise deals.
Compellent uses a 100 per cent indirect sales force with its channel sales focus. Does success in selling to larger enterprises require a direct sales force, the traditional route to getting enterprises to open their wallets? Gartner's Filks offered this thought: "Direct sales forces are always good for vendors but Compellent seems to be doing very well with the indirect channel model. The cost of a direct sales for smaller companies can be an inhibitor to growth as it is very costly to invest and create a world wide direct presence."
Storage blogger Martin Glassborow said: "[Storage Center 5.4] has a very powerful set of features but they'll struggle to get themselves in front of decision makers without a server partnership."
What else could be coming
Compellent's release is full of hints about what else is coming. The new product technology is a "foundation for flexible grid storage … a grid of Compellent arrays acting as one … a grid of shared storage that can be managed and optimised as one." With Live Volume "data is no longer physically bound to a particular array or data centre … [it] can be accessed and shared from multiple locations making Live Volume a key enabler for enterprise scale out and IT clouds."
What else might be coming to use up the new controller's processing power potential? Chris Evans said: "First on my list would be primary de-duplication. This would be (relatively) easy to support on the Compellent array because it already has data in chunks. The ability to have a single physical block of data mapped to multiple logical LUNs already exists with snapshots."
All that's needed is to locate duplicate data within the same tier and remove it. That would require some background scanning process (can't imagine a realtime version would work well). Data would never have to be "inflated" again because new data is written to new blocks, so the trawling process would continually be required (as was used in StorageTek's Iceberg)."
Compellent by the way is increasing its focus on Europe, looking to recruit more channel partners, and intends to hold a version of its annual C-Drive user conference in the UK next May.
A typical Storage Center 5.4 configuration starts at £48,000 (€56,000) and includes clustered Series 40 controllers, software licences Live Volume, Enterprise Manager, Data Progression tiering and Remote Instant Replay replication, and approximately 6TB of tiered 2.5-inch 6Gbit/s SAS storage. Live Volume licences start at under $5,000. In general, Compellent pricing is available from its channel partners and can depend on maintenance and software support options. ®
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