UNEXPECTED SOFT UPDATE INCONSISTENCY; RUN fsck MANUALLY

[Jeremy Chadwick]

On Mon, Sep 29, 2008 at 10:44:11AM -0700, Matthew Dillon wrote:
>     A couple of things to note here.  Well, many things actually.

Matt, I just wanted to take a moment to thank you for your verbose
and thorough outline of the issues as you see them.  You're the
first developer (albeit Dragonfly :-) ) I've seen to comment on
these in detail.

I fully agree with each and every item you covered, as well as the items
in your follow-up mail to Andrew (re: mentioning BIOS/software RAID and
hardware RAID at the end).

Going with ZFS as the default filesystem is really something we should
be considering seriously.  Oh, and yes, I *completely* agree with your
statement about the Foundation coughing up money to pjd@ for his
efforts.  ZFS "saving our asses" is how I put it too.  :-)

The topic of BIO_FLUSH is something I got to thinking about last night
at work; the only condition where a disk with write caching enabled
*would not* fully write the data to the platter would in fact be power
loss.  All other conditions (specifically soft reset and panic) should
not require explicit flushing.

I wonder why this is being done, especially on shutdown of FreeBSD.
Assuming I understand it correctly, I'm talking about this:

Waiting (max 60 seconds) for system process `bufdaemon' to stop...done
Waiting (max 60 seconds) for system process `syncer' to stop...
Syncing disks, vnodes remaining...3 3 3 2 2 0 0 done
All buffers synced.

-- 
| 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 |