But, what about updates?

• Ah yes, updates... That ssh loop sure was taking longer to run, and missing more machines each time.

• Any push based method is doomed. If you're triggering updates by push, you're doing it wrong :)

• Now, it's common to run apt-get or yum from cron and hope updates will mostly work that way.

• For those of you who have tried running apt-get/dpkg/rpm/yum on thousands of servers, you may have found that random failures, database corruptions (for rpm) due to reboots/crashes during updates, and other issues make this not very reliable.

• Even if the package database doesn't fail, it's often a pain to deal with updates to config files conflicting with packages, or unexpected machine state that breaks the package updates.