Most new products are upgrades of old ones. I don't mean in the senseof upgrade sales (although that too), but in terms of the code they'rebuilt from; they are revisions of existing codebases, not freshlywritten from scratch.

This has extremely rational economic and developmentreasons, as articulated by Joel Spolsky amongothers; there is a lot of money and value in existing codebases. Butignoring all the arguments about cost and captured knowledge and soon, there's another big reason

Recently, we had an interesting fire drill that actually winds up beingthe first decent argument for periodically rebooting good servers thatI've seen.

We have a number of very important servers, the kind of importantservers that are active all the time and that have their downtimescarefully scheduled well in advance. Recently, we (and by this I mean 'aco-worker') had to patch the OS on a couple of them in the pack. Thiswent fine.

As part of patching the OS,