Q: Snow Leopard not recommended for XSAN

It would help if you could be more specific, but we are using 10.6.3 and Xsan 2.2.1 with good results so far. After a few more installations, with no problems, we should be able to bless it as fully vetted. Turning off extended attributes and Spotlight indexing can help -a lot- with stability as well.

If your use is mission critical, and you do not need to be completely current, 10.5.8 and Xsan 2.1.1 is a magic combination that I'll miss dearly. To call that combo bulletproof would almost be an understatement.

JM

For anything mission critical, you only upgrade when A) You must have access to a new feature-set, and B) When that feature-set is mature enough to be relied upon.

There are companies out there that are fine using software versions that are 10 years old (Windows Server 2000, 2003, Red Hat, etc) strictly because their requirements don't meet both of those criteria. It doesn't matter what the time-table is; you move forward with an upgrade when is necessary and safe. If you look at Apple's OS development, each major version usually hits it's stride around 10.x.4 or 10.x.6, and Snow Leopard is right on target.

I don't have a list of your requirements, but barring some minute issue, if you had to move forward today I would say you could do so with 10.6.3 and 2.2.1. But, unless you site specific concerns, there is no way to help you.

Which other SAN solutions were you looking at? All the other providers I know of are even more conservative in their timetables, unless you're talking about something like SAN MP, Fibrejet, Facilis, Nexsan, MetaSAN, or a NAS solution like Isilon, all of which aren't even comparable.

JM

How much you're willing to pay Apple for support can be a key determinate in this process.

Apple typically runs the support for the current and immediately previous releases, given recent practice. That's obviously 10.6 and 10.5, and 10.4 has largely fallen off the edge.

If you're into long time-lines for support or for mission-critical (MC) or life-critical (LC) computing, there are other product lines and vendors that may be of interest. Apple is toward the leading edge of the upgrade cycle, doesn't tend to cater to enterprises, and sites requiring uptime tend to be best managed rather closer to the trailing edge of the product cycles.

If you want longer horizons, HP was still offering (not cheap!) support for some (also not cheap!) software platform configurations first shipped from 1992, when last I checked. (Some of those boxes regularly see and have seen uptimes measured in years, and one configuration I'm aware of was up and running for seventeen years. Also rolling upgrades for continuous access. But I digress.)

MC sites don't upgrade as a rule, and they end up testing heavily (preferably in parallel with production) when they do.

And there's no cookie-cutter answer here, either. I've not encountered two MC or LC sites with the same requirements.