Chris Evans over at Storage Architect posts aboutHardware Replacement Lifecycle Update
, on how storage virtualization can helpwith storage hardware replacemement. He makes two points that I would like to comment on.
... indeed products such as USP, SVC and Invista can help in this regard. However at some stage even the virtualisation tools need replacing and the problem remains, although in a different place.
Knowing that replacement of technologies at all levels are inevitable, IBM System Storage SAN Volume Controlleris actually designed to allow cluster non-disruptive upgrade, which we announcedMay 2006.
The process is quite elegant. The SVC consists of one or more node-pairs, and can be upgraded while the systemis up and running by replacing nodes one at a time in a sequence of suspend and resume. All of the mapping tablesare loaded onto the new nodes from the rest of the still active nodes.
I was hoping as part of the USP-V announcement HDS would indicate how they intend to help customers migrate from an existing USP which is virtualising storage, but alas it didn't happen.
Unlike the SVC, once cannot just upgrade the USP in place and make it into a USP-V. While it might be possible tounplug external disk from the old USP, and re-plug into the new USP-V, what do you do about the internal disk data?I doubt you can just move drawers and trays of disk from the old to the new. The data has to be moved some other way.
Some have asked why not just put an SVC in front of both the old USP and the new USP-V and transfer the data that way.While SVC does support virtualizing the old USP device, IBM is still testing the new USP-V as a managed device, and so this solution is not yet available, and would only apply to the LUNs in the USP-V, not the volumes specifically formatted for System i or System z.
An alternative is to take advantage of IBM's Data Mobility Services, the result of our recentacquisition of SofTek. IBM can help you both mainframe and distributed systems data from any device, to any device.
In a typical four year lifecycle of storage arrays, it might take six months or so to fill up the box, and might takeas much as a year at the end to move the data out to other equipment. SVC can greatly reduce both of these, so that you can take immediate advantage of new equipment as soon as possible, and keep using it for close to the full four years,migrating weeks or days before your lease expires.
technorati tags: IBM, SVC, Chris Evans, storage, architect, disk, virtualization, Invista, USP, USP-V, data mobility services, SofTek