How to cleanly mount /usr before init [solved]

kwesadilo · n00b Joined: 12 Jul 2010 Posts: 68 Location: United States

Back when udev changed so that you needed to mount /usr in the initramfs, I added a line to my initramfs' init script to do it. I don't think I did it quite right. Here is the whole script:

hydrapolic · Tux's lil' helper Joined: 07 Feb 2008 Posts: 126

Try to mark your /usr in fstab as noauto.

As for now, you mount /usr from initramfs, but you also have /usr in your fstab with implicit auto flag and localmount tries to mount it.

greyspoke · Apprentice Joined: 08 Jan 2010 Posts: 171

I ran into similar problems, can't quite remember the scenario, but roughly speaking I think it went like this.

You have already created your logical volumes in the initramfs and this is then confusing the lvm initscript, as it finds the volumes already activated yet the device nodes not there in the way it expects. (You might think they are there, but they weren't put there by udev and that seems to matter). If you are activating your logical volumes in your initramfs you don't need to run the lvm init script, removing lvm from your runlevels would deal with the first batch of whinges I think. Alternatively you could activate just the /usr volume in your initramfs and tell your lvm.conf only to deal with the other volumes, then probably the lvm init script wouldn't complain.

The later issues appear to be because you have already mounted /usr but your /etc/fstab is telling your computer to mount it which it can't do because it is already mounted. You appear to have set fstab not to check it as there are no complaints at the "Checking locak filesystems" stage and it clearly isn't trying to check /dev/mapper/vg-usr.

If you want your /usr to be checked you will have to put the necessary tools in your initramfs and have it checked there.

The Doctor · Moderator Joined: 27 Jul 2010 Posts: 2678

This may not exactly solve your problem, but separate /usr is working again with udev for me. I have a similar setup. You might want to make a new initramfs to test if it works for you as well. Clearly, you should keep the old one, just in case.
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kwesadilo · n00b Joined: 12 Jul 2010 Posts: 68 Location: United States

Thanks for answering. I figured it had something to do with fstab. I will try to fix this up and let you know how it turns out.

I had the lvm init script enabled because the elog messages made it sound like I needed it. Is it getting freaked out by the line lvm vgchange -a y? I'm pretty sure localmount or something will take care of mounting my logical volumes without the lvm init script. Right?

I was never quite clear on why I have to pre-mount /usr. Are you saying I might not have to? What determines whether I have to?

The Doctor · Moderator Joined: 27 Jul 2010 Posts: 2678

Well, the systemd guys broke it in the name of whatever and the Gentoo devs reversed this quietly. Bascially, there has been a push to move things from /lib to /usr/lib so of course they can't be used before /usr is mounted.

You can probably get by without premounting now. What would fail is a service that starts up and requires access to /usr before its ready. The only example that jumps to mind is alsasound when run in the boot runlevel. It really makes no sense to run it in the boot run level anyway. Default makes more sense and will not throw errors. There may well be others. My system is *kit, pam, and upower/disks free so I don't know if any of those will affect you.

The best advice I can offer is to try it. You will not hurt anything if it fails, and you will know for sure.

If that fails, you might want to try somthing like this:

greyspoke · Apprentice Joined: 08 Jan 2010 Posts: 171

depontius · Advocate Joined: 05 May 2004 Posts: 3509

As a very minor, very simple change, I note that you do not "vgscan" before doing "vgchange -a y". I have used lvm, but not very intelligently, so I've always followed the rules by rote, which include the 2-command sequence.
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kwesadilo · n00b Joined: 12 Jul 2010 Posts: 68 Location: United States

Wow, sorry I took so long to get back to you guys. It's been over a month. So here's what happened: The week after I first posted, I started shopping for and bought a car and started a job an hour away from my house. Since then, much of my remaining free time has been spent looking for apartments closer to work. So much, in fact, that I didn't reboot for long enough to forget the passphrase to my encrypted volumes a little over a week ago. I could still mostly remember how to touch type it, so I had a go at brute forcing it. That project was concluded successfully last night, and I was finally able to reboot.

I stopped mounting /usr in the initramfs. This got rid of the /usr-related errors during init. I have rebooted several times and observed no ill side effects during init or otherwise. systemd? More like systemFUD.

I could have sworn that I had vgchange in my init script. I must have deleted it at some point, maybe when I added the /usr line. I added