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HDS Still Looking up at SVC Bar

This week has been so busy I have not had time to sit down and put together some thoughts around a topic that I think needs time to explain.  There was big news coming from HDS this week around their new non-disruptive upgrade software as part of their VSP.  It looks like you can now do a non disruptive upgrade when migrating from Hitachi virtualization controllers.  Seeing they have the USP, NSC 55, USP V, USP VM  I can see why they would need something to help people get from one platform to the next.

One has to ask why so many different and separate systems. Could it be due to a growth in separate lines of business or just acquisitions that are now being integrated into the VSP line?  HDS has a history of telling customers I’m sorry in order to get the performance you need you have to get the forklift and buy this new shinier widget.

But just you can migrate, doesn’t mean you can keep those older models of VSP.  HDS in the past has not allowed different versions of the virtualization controller (USP) or between the USP and VSP.  IBM SAN Volume Controller (SVC) allows various models of the hardware engine to be mixed as long as they run the same version of software.

A couple of things I have noticed over the years about the HDS VSP.  The system does not scale in throughput beyond the capabilities of the single VSP (or USP) storage array that hosts the virtualized environment.  Even though HDS will claim the VSP can scale out to two control chassis it is really a single global cache system with an extended switched fabric.  The IBM SVC has no architectural limitation in scale out clusters.  This is shown in the latest SPC benchmark with a system that has 8 nodes in a cluster.

I also have a problem with HDS requiring all volumes that use the SSD drives to be thin provisioned.  In addition, they require external storage to be configured as the lowest tier.  This doesn’t really come into play unless you want to do Dynamic Tiering between two external storage resources.  IBM SVC can perform the Easy Tier process between internal to external with both thin and thick provisioned volumes.

When I started to really thinking about how customers who use Texas Memory RAMSAN or Violin Memory 3200 and how SVC could bring more intelligence in how data moves in and out of those systems, it made the VSP look like it was HD DVD and SVC is more Blu-ray.

I also have a customer who wants to do spit IO group clustering that would enable his active/active data collaboration for a distance of roughly 300km.  With quorum disks, the split IO group can be used for automated disaster recovery with a RPO and RTO of zero. USP and VSP doesn’t allow for this capability.

Now not everything is bad, I did read on Claus Mikkelsen’s blog that VSP supports the mainframe FICON protocol. He does go on to say that VSP is the only platform that supports virtualization for the mainframe.  That might be true but I think why does mainframe customers want their storage virtualized?  It’s not like they want their ERP solution that runs their multi-billion dollar business running on the same disk that the geek down the hall is using as a quake server. If you are running a mainframe, its probably best to keep your data on the proven DS8800.  nuf said.

I do applaud HDS for the effort and wish they would spend some more time trying to get to the same standard as that of the SVC.  But with this latest pass, they fall a little short but maybe they can spend time watching videos on their HD DVD player.


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