I just came across an unanswered question from 2012, asking about an issue with the Archlinux boot process.
It's now been several years and the Arch boot process changed a lot (switched to Systemd, etc). The question seems irrelevant, the author moved on, and it doubt anyone would still be running such an ancient configuration now (especially on a rolling-release distribution).
What is the right flag to use for this question? None of the predefined reasons seem to fit.
No specific action is required. Old questions don't need closing simply because they are old and/or outdated.
All posts are dated and people sufficiently literate to use a search engine to find an older Q&A should be capable of reading the date that accompanies every post even when a specific release/version number is omitted.
Also people may even be searching specifically for old information because they're dealing with a legacy system.
Questions that get no love get deleted automatically by the system after a certain expiration time.
The fact that this hasn't happened here is one indication that at least at the time when the question was posted it was considered a suitable post.
Questions older than 30 days can't be migrated, but if by current standards it is no longer a suitable post, then one of the other existing pre-defined close reasons can be used and should suffice.
You can also still down vote the question (which may result in the question getting re-evaluated by the system triggering automatic deletion).
I don't believe that we must do anything about such a question if it is on topic for ServerFault. Someone could still answer this (even if it is unlikely) and someone found it worthwile enough to upvote or else the post would have been deleted by now.
If there is no predefined reason that fits, you can use a custom reason. That will give you the option to describe your own reason. Then, everyone else who gets it in their close review queue can see your custom text, and either agree or disagree, just as they would with one of the standard reasons.
