5.2-RELEASE - Show stopper problem

[Dan Nelson]

In the last episode (Jan 11), Ted Wisniewski said:
> Thanks for your response...  As you can see in this output from the
> ps command you suggested, the processes are dfinitely waiting on the
> disk. BTW..  The syste in question was a fresh install from yesterday
> with no users other than myself (I did the cvsup to get it to
> 5.2-RELEASE).  It did hang when I did that with a similar result. 
> One of the "install -s etc.." processes went into the same state.
> 
> Output from PS:
> 
>  1805 ufs     ??  D      0:02.10 find /usr -xdev -type f ( -perm -u+x -or -perm
>   737 getblk  p0- D      0:02.14 find /usr -xdev -type f ( -perm -u+x -or -perm
> 
> These have been running for about 9 hours now, on a base system with
> nothing extra installed.  Originally, I thought it had something to
> do with the raid controllers on the various machines I tried,
> however, I was able to duplicate the condition on an ATA based system
> (I had to work a lot harder at getting the condition to occur on it). 
> It is almost like the I/O is too fast and something happens..

Are you seeing any errors in dmesg or /var/log/messages?  I haven't
seen any other reports of I/O hanging, so it might still be something
to do with your hardware or kernel config.

> On my test system the machine will run for days with this happening,
> however, I have another system that is actually doing a lot of
> I/O....  eventually it crashes (well locks up completely)...  If
> there is any particular info you might need, I am willing to do what
> I can.

If you can drop into ddb when it's locked up, I think there are some
commands you can run to print the kernel locks held by all the
processes, but I'm not sure what they are or how to interpret the
results.

-- 
	Dan Nelson
	dnelson at allantgroup.com