I told the customers (via a change coordinator) that my work will take maybe 15 minutes, with a restart of all affected Apache web servers. To allow for mistakes and problems, I asked him to organize a change window of 60 minutes.

The customers now want a precise time frame when the web servers will be unavailable. Of course, I can not provide this: Not only do I not know exactly how long the work will take me, I can not say what problems might crop up.

The change I have to do is part of a long standing series of changes, all necessary simply to implement what amounts to trivial, cosmetic changes. And frankly, my patience with them is at an end. I’ve told them that I cannot ensure that I will be ready by a time X. If that does not suit them, I can happily take the web servers down for the whole duration of the change.

Let’s see what they prefer.