Don MacVittie explains that you have a switch that connects various SAN arrays and when your arrays become over-burdened:
“I was pondering over the weekend the concept that a SAN is relatively easy to manage – at least on the surface – because it is, in essence, a network in and of itself. Separated from the IP network, you have a switch that connects various SAN arrays and when your arrays become over-burdened, you can just drop another one in and plug it into the switch. Easy. And since the switch is not generally from the same vendor as the storage array, you can plug in whatever array you find most appealing this week. Migrating data between arrays can be tricky, but these days there are solutions for that. Initialization can be painful, particularly if you want to add it to an existing pool and distribute data across it like it had always been there or you’re using at-rest encryption, but that’s just time you have to wait while it runs, your staff isn’t required unless something goes wrong.
Whither the same type of adaptability and expandability in the NAS space? That’s where devices like our ARX come in. It sits between your machine and your storage, it cares not how much or what brand of storage sits behind it (in fact, at least for ARX, you can even point it at random shares on your Windows servers if you feel the need), and it allows you to just plug in more disk space and manage it centrally. You have the same issues with initial config that you would otherwise have, but the box is then part of the File Virtualization product’s virtual directory, and can be accessed, moved about, whatever.
This is the part where NAS vendors start to huff and puff and talk about their astounding management and integration, and how easy it is to add storage to the system, etc. etc. etc. And they are 100% right. Modern NAS systems are astounding in their versatility and ease of management. As long as they’re homogeneous systems. Throw another vendor on the network and ask the same questions again. You’ll get a set of answers that makes it clear these tools are only for their products.
And that’s one of the many many reasons why a high-quality File (NAS) Virtualization product is more than a little useful. They generally don’t cater to one vendor, they give you all the things you have if you are a single-source shop, but you can apply it to whatever NAS – or even Windows Shared – storage you have in the house. Simplified management, ease of data movement when necessary, you name it. All across whatever hardware you happen to have today or will have in the future.”
source: sys-con.com (101/07/2009)