Re: Autoconfiguring root device and fstab(5) (wedges?)

[christos%astron.com@localhost (Christos Zoulas)]

In article <4D8DD4F3.8090009%free.fr@localhost>,
Jean-Yves Migeon  <jeanyves.migeon%free.fr@localhost> wrote:
>Hi list,
>
>I am currently adding support for Xen dom0/domU with anita, our
>automated installation and testing tool.
>
>The current system uses QEMU to install a full-fledged OS to run ATF
>tests. For convenience, I would like to reuse the same image for testing
>native, dom0 and domU environments.
>
>Thing is: the root device is different for domU and native/dom0 (xbd0 vs
>wd0). This causes failures everywhere during boot, due to improper
>fstab(5) entry for /.
>
>Andreas suggested me to try wedges. They do work, as they autoconfigure
>properly, but current kernels do not have DKWEDGE_METHOD_BSDLABEL turned
>on by default (and won't have it in the near future I believe, given all
>the breakage it imposes with current setups).
>
>Any other way to autodetect root device while keeping fstab(5)
>untouched? I want to avoid newbtconf(8) (this will need a couple extract
>commands in anita to use it), or playing dirty tricks with symlinks to
>different fstab(5) depending on boot device...
>
>I tried to use dkscan_bsdlabel(8) together with sysctl kern.root_device
>very early during boot (/etc/rc.conf.d/fsck_root), however it returns
>"Device busy", so I can't use it to circumvent the missing
>DKWEDGE_METHOD_BSDLABEL options(4).

If fstab is the only thing that breaks, perhaps we can automate the fstab
conversion for at least ffs...

christos