Gentoo Archives: gentoo-dev

From: Joost Roeleveld <joost@××××××××.org>
To: gentoo-dev@l.g.o
Subject: Re: [gentoo-dev] udev and /usr
Date: Thu, 15 Sep 2011 22:13:59
Message-Id: 6080144.TD9jt0YPcQ@eve
In Reply to: Re: [gentoo-dev] udev and /usr by Zac Medico
On Thursday, September 15, 2011 01:34:50 PM Zac Medico wrote:
> On 09/15/2011 01:03 PM, Joost Roeleveld wrote: > > But, with udev then failing, will there be the /dev-entries to mount the > > different partitions to fix the environment? > > I the preferred approach is to enable CONFIG_DEVTMPFS=y and > CONFIG_DEVTMPFS_MOUNT=y, so that the kernel populates /dev for you > automatically.
Will this be sufficient for "localmount" to get the system to work correctly? It is my understanding that some udev-scripts are the actual problem that is being solved with this? I wasn't aware of these kernel options also being required.
> >>> Also, I was actually hoping for a reply to the rest of my email as > >>> well, especially the idea for splitting udev into 2 seperate > >>> processes.>> > >> In essence, what your doing here is playing a game of "let's see how > >> long we can delay the mounting of essential filesystems". If you play > >> this game, then again, you expose yourself to the possibility of > >> unsatisfied dependencies. Therefore, the only foolproof approach is to > >> mount all essential filesystems as soon as possible (via initramfs). > > > > True, but I don't have any scripts configured for udev on my desktop. > > My server has some scripts related to Xen, and those are all under > > /etc/xen/... > > > > In this case, would it still be necessary to use an initramfs? > > Well, as long as your essential filesytems aren't mounted before init is > called, there's always the possibility that some issue of unsatisfied > dependencies will arise in the future. Therefore, the most foolproof and > future-proof approach is to have them all mounted before init is called.
With systemd, one of these is the dbus-stack. Yes, I'm aware of this. But, if systemd isn't used, init should work. Or have I missed something about init being deprecated for systemd? I think systemd is nice for desktops/laptops. But on servers it seems to be overkill to me and as I umount filesystems as part of my backup-scripts, having something force-mount them in the background is going to kill those scripts. But this bit is off-topic.
> >>> If someone can explain to me why my idea won't work, please let me > >>> know.>> > >> If your goal is to expose yourself to the possibility of unsatisfied > >> dependencies, they your idea will achieve it. > > > > No, my goal is to come up with a different solution to this problem > > which, on my system and possibly also on a lot of other systems, > > doesn't actually exist. > If a problem doesn't exist now, that doesn't mean one won't arise in the > future. As said, the most future-proof approach is to have them all > mounted before init is called.
Or, if I am not mistaken, before udev is started when not using systemd. -- Joost

Replies

Subject Author
Re: [gentoo-dev] udev and /usr "Michał Górny" <mgorny@g.o>