To upgrade or not to upgrade?
That’s another great sysadmin’s dilemma: do you do updates often, trying to keep your systems at the “cutting edge” and have all the security patches upplied immediately upon official release, or do you roll the updates out as discretely as possible, not trying to fix something that’s not [still] broken? That, and the fine topic of PXE, is discussed in the Chapter 6 of the “UNIX and Linux System Administration Handbook”.
On one hand,
gratuitously upgrading systems costs time and money
Those who put these principles into practice must be willing to collect an extensive catalog of active releases.
On the other,
Patching outdated versions of the operating system is often infeasible, so administrators are faced
with the choice of skipping updates on some computers or crash-upgrading these machines to a newer internal release.
So what do you do? That’s your artful choice of balance between the two extremes.
Another controversial point of the chapter, about the notable superiority of APT over YUM – they go as far as talking of APT as a superset of YUM, – makes me once again question, why would someone willfully choose Red Had or CentOS over Debian or even Ubuntu, barring the corporate pressure?