background fsck can be dangerous!

[Brian Fundakowski Feldman]

On Wed, Jun 29, 2005 at 03:12:37PM +0100, Steven Hartland wrote:
> I've not had a single crash / power outage that background fsck has
> been able to deal with. 90% of the time the machine will fail to even
> boot to single user mode :(

You should turn write caching off on your drives.

>    Steve
> ----- Original Message ----- 
> From: "Niki Denev" <ndenev at icdsoft.com>
> 
> >I want just to share my last experience with the combination of
> >power failure + background fsck. After the power returned and the 
> >machine booted, it sheduled background fsck after 60 seconds, but
> >at this point most of the services were already started, and some of them 
> >seemed to rely on files that were probably in unclean state before the 
> >check.
> >This unfortunately leaded to some lost email...after the fsck completed,
> >everything runs ok, but i have now set background_fsck to NO in rc.conf.
> >
> >Here is a sad sample from my qmail log file :
> >@4000000042c1badc24fc21cc delivery 1: 
> >success: 
> >/libexec/ld-elf.so.1:_Shared_object_"libpq.so.3"_not_found,_required_by_"dspam"/did_0+0+1/
> >@4000000042c1badc24fff25c status: local 2/30 remote 0/20
> >@4000000042c1badc250151ec delivery 4: 
> >success: 
> >/libexec/ld-elf.so.1:_Shared_object_"libpq.so.3"_not_found,_required_by_"dspam"/did_0+0+1/
> >@4000000042c1badc2502bd34 status: local 1/30 remote 0/20
> >@4000000042c1badc25050ef4 end msg 23982
> >@4000000042c1badc2508b0a4 delivery 2: 
> >success: 
> >/libexec/ld-elf.so.1:_Shared_object_"libpq.so.3"_not_found,_required_by_"dspam"/did_0+0+1/
> >@4000000042c1badc250a9cd4 status: local 0/30 remote 0/20
> >@4000000042c1badc250c7d4c end msg 24087
> >@4000000042c1badc2510942c end msg 24040

The filesystem looks the same before, during, and after background
fsck runs, other than the free space information.

-- 
Brian Fundakowski Feldman                           \'[ FreeBSD ]''''''''''\
  <> green at FreeBSD.org                               \  The Power to Serve! \
 Opinions expressed are my own.                       \,,,,,,,,,,,,,,,,,,,,,,\