Long boot delay "Mounting Root Filesystem"

[David Abrahams]

I just upgraded the kernel of my Thinkpad T60p from linux-386 to
linux-686-smp, and suddenly there is a long delay at boot in the
"Mounting Root Filesystem" step.  The root filesystem is an LVM
logical volume on an SATA drive.  If I go back to the 386 kernel (same
version) everything is fine -- well it takes 4-5 seconds to wake up at
that step, which could be a manifestation of the same problem, but it
still seems tolerably fast.

With linux-686-smp, the disk sees a couple short bursts of activity
during the beginning of this period, but nothing really proceeds for a
good 40 seconds--sometimes longer--and usually not unless I press some
keys on my keyboard and add some trackpad/button activity. Eventually
it will wake up and continue if I give it physical stimulus, but it is
really annoying to have to endure such a slow boot process just to
make my machine run faster after it boots ;-)

Does anyone have a clue what might be going on here, or how I could
diagnose it?

Thanks in advance,

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com