Softupdates not preventing lengthy fsck

[Scott Long]

Kris Kennaway wrote:
> On Tue, Apr 12, 2005 at 05:01:49AM -0700, Don Lewis wrote:
> 
>>On 11 Apr, Kris Kennaway wrote:
>>
>>>On Mon, Apr 11, 2005 at 06:43:17PM -0700, Don Lewis wrote:
>>>
>>>>On 11 Apr, Kris Kennaway wrote:
>>>>
>>>>>I'm seeing the following problem: on 6.0 machines which have had a lot
>>>>>of FS activity in the past but are currently quiet, an unclean reboot
>>>>>will require an hour or more of fscking and will end up clearing
>>>>>thousands of inodes:
>>>>>
>>>>>[...]
>>>>>/dev/da0s1e: UNREF FILE I=269731  OWNER=root MODE=100644
>>>>>/dev/da0s1e: SIZE=8555 MTIME=Apr 18 02:29 2002  (CLEARED)
>>>>
>>>>>/dev/da0s1e: UNREF FILE I=269741  OWNER=root MODE=100644
>>>>>[...]
>>>>>
>>>>>It's as if dirty buffers aren't being written out properly, or
>>>>>something.  Has anyone else seen this?
>>>>
>>>>This looks a lot like it could be a vnode refcnt leak.  Files won't get
>>>>removed from the disk while they are still in use (the old unlink while
>>>>open trick).  Could nullfs be a factor?
>>>
>>>Yes, I make extensive use of read-only nullfs.
>>>
>>>Kris (fsck still running)
>>
>>It would also be interesting to find out why fsck is taking so long to
>>run.  I don't see anything obvious in the code.
> 
> 
> I can take a transcript of the entire fsck next time if you like :-)
> (it ran for more than 5 hours on the 24G drive and was still going
> after I went to bed)
> 
> Kris

Don might not know that your workload involves creating and deleting
full ports/ trees repeatedly, and those trees contain hundreds of
tousands of inodes each.  If there is a reference count leak and those
deletions aren't ever being finalized, then there would be a whole lot
of work for fsck to do =-)  Might also explain why disks have been
unexpectedly filling up on package machines (like mine).

Scott