Re: [gentoo-user] LVM, /usr and really really bad thoughts.

[Canek Peláez Valdés]

2012/3/11 Jorge Martínez López <jorgeml@×××××.com>:
> Hi!
>
> I had some struggle with a separate /usr on top of LVM and the dracut
> thing. I noticed that udev was complaining at boot that it could not
> find some scripts.
>
> The usmount dracut module did not work for me because it could not
> find /usr. So what I did was to include the fstab-sys smodule in
> dracut:
>
> /etc/dracut.conf
>
> # Dracut modules to omit
> omit_dracutmodules+="usrmount"
>
> # Dracut modules to add to the default
> add_dracutmodules+="fstab-sys"
>
> Then I created /etc/fstab.sys with just the /usr partition
>
> /dev/disk/by-uuid/90d82b02-e6c2-4011-940e-783d12b0c4fe          /usr            ext4            noatime         1 2
>
> Dracut could only find the partition by using the uuid (use blkid to
> find it easily).

> The next step was to remove /usr from /etc/fstab to prevent /usr from
> being mounted twice (the boot process does not like it).

Mmmh. Could you try to use LABEL= in /etc/fstab (not /etc/fstab), and
see if that way it gets mounted, and only once? The udev developers
recommend using either UUID or LABEL; and LABEL it's easier (and
prettier) to set.

> The last obstacle is /etc/mtab. By the time /usr is mounted I believe
> / is mounted as read only, so mount cannot update /etc/mtab. The
> trivial solutions is to delete /etc/mtab and make it a symlink to
> /proc/mounts . In that case it is always up to date.

I think the link is to /proc/self/mounts; /proc/mounts it's a link to
it, actually.

> Of course, YMMV. Be careful when changing things that can prevent your
> machine from booting and make sure you have a live CD at hand.

Good advice. Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México