Machine hanging on synchronize cache on shutdown 2.6.22-rc4-git[45678]

[Brad Campbell <brad@wasp.net.au>]

G'day all,

I've got a box here based on current Debian Stable.
It's got 15 Maxtor SATA drives in it on 4 Promise TX4 controllers.

Using kernel 2.6.21.x it shuts down, but of course with a huge "clack" as 15 drives all do emergency 
head parks simultaneously. I thought I'd upgrade to 2.6.22-rc to get around this but the machine 
just hangs up hard apparently trying to sync cache on a drive.

I've run this process manually, so I know it is being performed properly.

Prior to shutdown, all nfsd processes are stopped, filesystems unmounted and md arrays stopped.
/proc/mdstat shows
root@storage1:~# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
unused devices: <none>
root@storage1:~#

Here is the final hangup.

http://www.fnarfbargle.com/CIMG1029.JPG

They keyboard is responsive up until the "hard resetting port" when it just locks solid and requires 
a power-cycle.

It's not really something I want to bisect if I can avoid it give the lovely noise it makes when I 
power it off. (this box only has a hard power switch, no reset or soft power buttons)

Brad
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