Bill Campbell wrote:
Of course we don't do things that are likely to take a critical service down without proper prior planning (often found out the hard way on our own systems :-). If an update is likely to have an impact on operations, it is scheduled during a maintenance window.
In other words you'd dedicated sufficient human resources to undo whatever damage the package management system causes...
Isn't that what our customers are paying us to do?
That has to be true now matter how one is doing updates.
Yes, but the extent to which it is actually required depends on how badly the intended automation fails. I think at least in theory, the parts of config files that are likely to need user modifications are supposed to be extracted to /etc/sysconfig/... so the files included in RPM updates generally won't have local changes and can be replaced without regard to the old contents. And programs suitable for inclusion in an 'enterprise' distribution should be designed so as not to require non-backwards-compatible changes in updates.