Root mount from ZFS takes forever...literally.

[Jeremy Chadwick]

On Mon, May 17, 2010 at 06:47:02PM +0200, Pawel Tyll wrote:
> >> Boot process "hangs" on Trying to mount root from zfs:tank/root - I
> >> can import the pool from alternate boot source (PXE), and access files
> >> fine, but I can't finish booting the system from ZFS.
> > What messages do you have on screen when this happens?
> > Can you upload a screenshot somewhere and post a link?
> Just mounting root, and nothing happens. System is responsive,
> attaching/detaching USB keyboard generates messages, and hitting
> alt+ctrl+del correctly reboots the system.
> 
> After messing around with fstab (added / entry, bit redundant with
> loader.conf vfs.root.mountfrom entry) it started to working again, but
> I can't repeat it now by removing this. Too bad I didn't take a
> snapshot before fixing :(
> 
> Strange. :)

Are you *absolutely sure* the problem has to do with ZFS?  I see you
mention PXE booting......

This sounds much like an environment where serial console is set up
incorrectly; kernel messages will be seen up to the final "Mounting
root..." message, but everything past that goes to VGA console (or
serial console, depends on the configuration mishap).

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |