kern/149803: [patch] loader: set vfs.mount.rootfrom using label

[vwe at FreeBSD.org]

Synopsis: [patch] loader: set vfs.mount.rootfrom using label

State-Changed-From-To: open->feedback
State-Changed-By: vwe
State-Changed-When: Thu Aug 19 19:40:56 UTC 2010
State-Changed-Why: 
Thomas,
I tend to close this PR but would like to discuss that before.
A lot of machines I'm responsible for, do not have an /etc/fstab on the boot
filesystem at all, so loader(8) does not see anything at all.

If vfs.root.mountfrom is properly set, neither loader(8) nor the kernel
require any entries to find the root filesystem.

Thus, these machines boot and find the root filesystem without user
intervention and without an /etc/fstab.

All it takes is the correct filesystem type and device path to the device that
contains the root filesystem and that all can be set by loader.conf(5).
So in the end, what your PR is all about can be done without any code changes.
A code change for a problem that can be solved w/o a code change is IMHO
a KISS violation.

You can also use a glabel'd root filesystem. It's devicename at the mount
prompt is something like "ufs:ufs/MYLABELEDROOT". It just requires 
geom_label to be loaded at boot time.

If you're able to let your machine mount the root fs by just using proper
loader.conf settings, I would like to close this PR.

I'm wondering if you're able to set your root fs to be mounted at boot time, too?


Responsible-Changed-From-To: freebsd-bugs->vwe
Responsible-Changed-By: vwe
Responsible-Changed-When: Thu Aug 19 19:40:56 UTC 2010
Responsible-Changed-Why: 
track

http://www.freebsd.org/cgi/query-pr.cgi?pr=149803