Upgrade from 4.6?

[adealey]

I've tried to do research on this questions but haven't been successful.

It's embarrassing but I have two boxes which are still running obsd 4.6. I want to upgrade them to 6.1.

I know that only upgrades to the successive release are officially blessed but this would mean (if I take it literrally) twelve upgrades for each box.

So my question is, do I really have to iterate through each point release or can I get away with 4.6 -> 5.x -> 6.1

(BTW... for some odd reasons I'd rather not rebuild these boxes from scratch)

[e1-531g]

Originally Posted by adealey

So my question is, do I really have to iterate through each point release or can I get away with 4.6 -> 5.x -> 6.1

Yes. Even then I would bet that some configuration files changed syntax. You should test this environment, before putting this boxes to production again, and be ready to modernize config files.
Before doing upgrade or reinstall backup your config files via Git or some other version control system (cvs is in base system). Anything else worth to backup using tar(1) and copy to external storage. Alternatively clone entire HDD (or relevant partitions and MBR/GPT) to separate HDD.

[jggimi]

A reinstallation will be much easier.

Even though 15 upgrades might take only two hours for the upgrade scripts to run, and not even considering the manual architectural changes you would need to make according to each Upgrade Guide, you should know that:

• Most mirrors will be missing the bulk of your intervening releases. My nearest mirror only keeps them back to 5.5.
• There were significant changes to PF and PF syntax at 4.7.
• There was a major ABI change for the year 2038 for 5.5. This necessitated removing all third party packages before upgrading, then reinstalling new packages after the upgrade. If you had any locally built applications you would have had to do the same transition yourself.

[jggimi]

Oh, yes, here's another post to note that there were additional syntax and structural changes to PF at 5.5 for queuing. There was a transition period for two releases... one year ... to assist with that transition.

Throughout the intervening years, there have been many built-in application changes. Without thinking much about it, I recall major changes in Mail Transfer Agents (sendmail is long gone), web servers (OpenBSD's fork of Apache 1.3 -> nginx -> httpd). Huge changes in daemon management.

A transition of existing applications and services to a new, clean system will be much easier on you, and on those who use your servers.

[bsd-keith]

jggimi knows what he's talking about, so I'd listen to what he says there.

I'd also have suggested backing up your data, (which you already do, of course), & install afresh for the least amount of hassle.