ORIGINALLY POSTED 5th December 2007
8,268 views on developerworks
I guess I didn’t really get the message across in my previous post, well certainly not in the way I inteded from the emails and comments here.
The main point I was making was with respect to using a “vanilla” Windows install as the base operating system for a storage product, in particular one in which all your SAN traffic flows through – lose it and lose access.
What I meant was an install it yourself from CD, install all the service packs, download all the security patches, setup a firewall and anti-vrius – restrict access, turn off unwanted TCP/IP holes, turn off unwanted services, fiddle with the registry to get it to not load all the startup services you don’t need – etc etc. Then stick a Storage Virtualization software layer on it, get all the multipathing sorted, ensure you have the latest HBA drivers, BIOS, patches etc – Then stick this in the middle of your SAN and pass ALL I/O through it…. (now maintain the box)… What happens if someone mistakenly leaves the ‘auto-install updates’ option on and Windows decides it needs to reboot itself… ouch!
This is not my idea of fun or sensible. Oh and you are running it on a chosen Intel or AMD box, that itself will radically affect the performance you can get.
Contrast that with a system comprising a standard vendor defined planar, CPU memory complex, with a (presumably) cut down thinned, pruned, tightly controlled and tested version of Windows – essentially running in the same consistent manner on every system shipped (CLARiiON etc) that needs no maintenance or daily ‘windows update’ other than vendor supplied single packages.
The two are very different beasts, and I felt I needed to clarify.
Even better, use an OS where you can very precicely choose what you do and do not install down to a very precise level – kernel modules, services etc. Thats why we did it with SVC – and even wrote our own kernel memory modules to bring them to the level we needed. There’s no bloat in SVC, I make sure of that in my daily role. Anything that could cause wasted MIPs is gone.
Someone brought up the ‘open’ nature of SVC, or what they saw as a lack of openness. It depends on your definition of open.While we did considered making SVC open source, or at least the software available, its for the above reasons we chose to supply it on a specific hardware platform, use a specific customised OS. Combine that with the low latency internal hardware access, user mode running and complete control of the hardware that allows the performance and near 100% port utilisation that distinguishes SVC from the rest. SVC doesn’t claim to be ‘open source’ but it does, like other appliance solutions, provide a true solution to removing vendor lockin from your storage purchase descisions.