In these days I’m working to a big upgrade project for my first italian Compellent customer (2008).
In these two years a lot of things changed in terms of disks (capacity and type), software features, connectivity and so on. We are planning for a huge disk expansion, a major software update and a migration to newer generation controllers. All in one shot!
Since I’m talking about Compellent, this won’t cause big troubles, but what about a similar upgrade with an old style array? it could be a big pain in the “neck”.
If you think about a big upgrade, like this one, of an old generation storage array you face a lot of problems:
With an old generation array you are forced to think about expansion of disks only in terms of fixed technology options. i.e.: If the backend was designed to support FC/SATA disks you can’t plug new 2,5″ SAS disks.
While, Compellent Storage Center supports the mix of different disks types in the same system (SSD, FC, SAS, SATA). The storage industry is going to move very fast towards SAS because it is more reliable than FC and because you can mix different kind of disks in the same tray. Working with standard components permits Compellent to comply with industry trends without major constraints in the quickest way: this is a big advantage for the customer because they can chose the best fit for their needs every time without limitations!
With an old generation array it is not so simple to get new features. Storage vendors often develop new features only for newer controllers and if you want a new feature you think might be useful for your aged (but still good and in production) Array you can’t.
Adding new software features on Compellent (when they are released) is simple, just upgrade your controller’s software. Compellent has a different way of thinking and separates hardware from software… Nowadays you can find very old controllers working with the latest major software revision! All supported and without limitations.
This is another main advantage for the customer: he can stay up to date with new features without spending money for new hardware at least if they don’t need more power! Yup!
Normally, a controller upgrade for an old style array means the swap of the controllers with a service disruption, a SAN reconfiguration due to the change of WWNs and, sometimes ,a drastic change of the backend architecture forces the customer to a forklift upgrade (controllers+disks!!!). The costs of these operations are huge!
Controllers upgrades with Compellent are far simpler! When you upgrade from an old model to a new one you can do this operation with minimal impact to the production environment! If you don’t need to update your connectivity speed (i.e. changing IO cards), you can just switch off one of the old controllers (in a clustered system), move cards in the new one, reboot the controller, repeat the operation for the second controller and work is pretty done!
a brief recap
Updating an old style array could be a messy revolution in your datacenter! revolutions often bring violence (to your SAN), pain (to your services), new rules (imposed to your infrastructure management). Revolution results needs to be always measured and verified after some time… history teaches!
Updating a Compellent storage is an evolution! The storage adapts itself to your new needs, it’s a natural process (new and more efficient tools to do new and more demanding tasks), it is smooth process (no rough steps but slight and silent modifications to your production environment).
What do you like for your IT infrastructure? Revolutions or Evolutions?