[SOLVED] custom systemd targets and grub2 menu

[osce0]

Ok, I'm in the process of moving to Fedora 17 from Fedora 14. That means converting my custom setup of SysV/init+grub to systemd+grub2. And I have two questions.

1. If I create a custom systemd target, is there a way to tell systemctl to disable services only for that custom target? I couldn't find in the man page how to specify that. It looks like most services are already tied to an existing target like multi-user, so any changes (enable/disable) affect both the multi-user target and all targets that depend on it. I can't seem to tell to disable or exclude one service just for the custom target. Unless I create another separate copy of multi-user and other depending targets and manually modify them, which I would like to avoid doing.

2. If I want to create two separate menu entries in grub2 for each kernel versions (for running different custom systemd targets), is this going to involve learning the internals of grub2 scripts and writing a custom script? Or is there an easier way of justing editing some configuration file?

I don't mind doing the learning and script writing. I just want to know if there is a simpler alternative before I undertake this conversion effort.

[osce0]

I guess from no response, my guess was correct: I have to invest some time to learn grub2 script, and understand the hierarchical structure of systemd. Marking solved since it is not a problem, I just need to invest time to learn.

[stevea]

How do you intend to manage the systemd targets from grub2 ?

FWIW grub2 seems pretty direct and straightforward from my hacking. I doubt it will ne a big learning curve.

systemd is a different story. The motivation for it's design is obtuse. The implementation of targets & servies, even in F16 is certainly imperfect ('feels' somewhat better in F17). The utility documentation is not sufficient, Lenart Poeterings blog paper are pretty useful.

Note that you can use your legacy /etc/init.d inisrcript with systemd. So you can switch first and play with systemd later.
I

[osce0]

Thank you for the info, stevea. I'm still learning the systemd to see if I can create a custom target that I can switch back and forth.

So far, it was a miserable experience. I spent 4 days on it and can't find a solution.

Here are some basic steps that I did:
1. Copy everything in /etc/systemd/system/multi-user.target.wants to /etc/systemd/system/custom.target.wants
2. Copy /usr/lib/systemd/system/multi-user.target to /etc/systemd/system/custom.target and just change one line: Description=Custom

I thought this was enough to start, but no way. When I enter the boot parameter in grub2 as systemd.unit=custom.target and reboot, it behaves differently:

The virtual console will not come up until I ssh into the machine remotely.

I was hoping to have a custom target with wired network off and wireless on for road warrior mode, which I had it working in previous Fedora by using sysv init level 2.

Going back to init.d initscript as you suggest.

---------- Post added at 08:24 AM ---------- Previous post was at 08:14 AM ----------

Hmm, after reading my post, I finally realized that multi-user.target.wants has services in /usr/lib/systemd in addition to /etc/systemd. Guess I'll have to hack away for a few more days.

---------- Post added at 08:34 AM ---------- Previous post was at 08:24 AM ----------

Phew, that solved it. So I had to check both /etc/systemd/system/multi-user and /usr/lib/systemd/system/multi-user to see if any service needs to be copied to custom.target.