"An Enterprise Needs Only Four Computers"
By davew on Jul 11, 2007
With a tip of the hat to Greg P's posting here (and I thought the quote was attributed to Ken Olsen rather than Thomas J Watson...), I'd like to consider the individual enterprise, and propose that an enterprise only needs four computers.
The four computers in question would comprise two clusterable-or-otherwise-resilient systems in a primary datacentre, and two clusterable-or-otherwise-resilient systems in a business continuity or disaster recovery location. Each of these systems would most likely be populated with some x86 / x64-based boards and some SPARC-based boards. The boards would be grouped into physical domains (where provable, rather than merely certifiable, data segregation is required and covert channels are perceived to be a potential issue if other technologies are used), and physical domains would be sliced up into LDOMs on the SPARC side and (most likely) Xen domains on the x86 / x64 side, where either certifiable data segregation is required or OS-level admins need full independent control of their OS instance (eg, for running different OS versions or different patch levels, etc). Applications would live in zones.
User home directories would need their own OS instance, up until the point where a non-global zone is able to function as an NFS server. Doubling the home directory servers up as Sun Ray servers may also be sensible.
There's enough flexibility and granularity here, given sufficient attached storage, to run wellnigh any enterprise, if the computers are big enough. In fact, I suspect that a great many medium-sized enterprises could probably get by on four fully-loaded Sun Blade 6000 systems, at a pinch.
Now, I love reductio ad absurdum as a device of reasoning - I find that, sometimes, what pops out at the end of such a chain of reasoning may not be as absurd as first expected :-).
The reasons why you don't see enterprises running this way yet are, for the most part, human rather than technological. In particular, admins often feel uncomfortable about the fact that their envronment can potentially be affected by a "higher authority".
To give some concrete examples, if systems belonging to departments A and B in an organisation are consolidated into a pair of zones on a single host, each zone admin would have initial oncerns about who owned root in the global zone. Even if the systems were consolidated into logical or physical domains on a sizeable system, each domain admin would have initial concerns about who had root on the domain controller. Granted, such issues would very likely be alleviated in policy, but at the end of the day you'll still see some circumstances where admins, accreditors and auditors have issues about not being the ultimate authority with final control over a system.
This is why you're not likely to see an enterprise running on just four computers, just yet.