Thanks for the insight, Dave. You are correct that there is often little reason for concern of what's "under the hood", as long as it has the horsepower to handle the task at hand.
It's much like shopping for a toaster - you just get one that will make 2 slices, 4 slices, or whatever.
However, what if I'm Mr Holiday Inn and I want to put toasters in 300 rooms? I want them all the same for reasonable repair and maintenance budgeting. Differences under to hood show up at the worst possible time - when things are broken. And then, there's always that "toaster envy" if one is nicer than the other.
Perhaps our shop has finally outgrown the stage where appliance oriented filers are a practical solution. On the front end, the price is very attractive, but it looks like I'm about to have to support 4 different architectures under the hood, with only 5 filers in house! The maintenance costs on these 5 comes out to about $65,000 per year for 4-hour response on about 500G of available storage. This looks a bit like an A*sp*x price quote...
Dave Hitz wrote:
One of the big advantages of the appliance approach is that the CPU makes no difference to the user, so we are free to use the best chip available at the time. (Pop quiz: What chip is in your Cisco router?)
We do our internal development on SPARC chips, because we have a filer simulator that runs as a UNIX process under SunOS, and of course we've shipped both x86 and Alpha products.
As a result, we've already debugged the portability issues associated with 32-bits vs 64-bits, CISC vs RISC, and big-endian vs little-endian. (Actually, CISC vs RISC doesn't really have any portability issues, but it makes the list longer. :-)
If I were developing a general purpose system, I would be very afraid of the Alpha, but for an appliance the choice was easy because the performance, especially for data-moving functions like file service, just can't be beat.
I don't mean to imply that there's no overhead associated with changing chips, because there are compiler issues and test issues and boot PROM issues and performance issues. But in the grand scheme of things, switching chips isn't that big of a deal.
Dave