Subject: Re: hang during shutdown
To: None <firstname.lastname@example.org>
From: maximum entropy <email@example.com>
Date: 09/10/1997 23:56:31
>From: Tim Janes <firstname.lastname@example.org>
>> Simon Burge <email@example.com> writes:
>> I saw this at least on three machines, but not so often. They prints
>> 'syncing disks' and hang. I'm not yet looking in this problem, but it
>> seems process are waiting struct buf.
>We run some 20+ Pentium-Pro's with a common NFS mounted /usr. Since
>upgrading from 1.2.1 to 1.2G this shutdown hang is rock solid on all machines.
>I have checked that shutdown works OK if I use /usr on a local disk,
>so seems related to nfs.
>I am happy to try some debugging but don't really know how to start.
>When in the hung state the machine responds to ping but otherwise appears dead.
I submitted PR kern/4093 about this problem on Sunday. I wasn't able
to find a fix but I was able to figure out where the hang is
I *think* there are two distinct problems here, because the NFS /usr
dismount hang seems to happen *before* the "syncing disks" message.
entropy -- it's not just a good idea, it's the second law.