Is there any way to eliminate the need for a manual fsck?

I haven't lost any data yet, but I have had to make a couple
of 80 mile (133km) round trips to my colo facility to run
a fsck...

Thanks,
  Dave Melton

> On Wed, Apr 23, 2003 at 11:20:52AM +0200, Bruce Martin wrote:
> > This is just a request to see if NetBSD 1.6 has included any measures to
> > increase the robustness of filesystem integrity when systems are power
> > cycled without being shut down properly. Under the 1.5.* distributions 
> > (on i386 specifically) we have had quite a number of problems where
> > fsck's have either failed and needed to be run manually from single
> > user mode, or where we have actually lost files and directories.
> 
> NetBSD has *always* had measures to prevent these problems, at last without
> softdeps (I've got some problems with softdeps too).
> Now, there are issues with the drives. Some drives have a write-back 
> cache, which mean they claim to have wrote the data to media when 
> it's actually not done. Worse, they can reorder writes internally, 
> which mean the OS doesn't have much control on what is really on 
> disk and what is only in the disk's cache, and can't guarantee 
> filesystem integrity on unclean shutdown. Basically, IDE disks have 
> write-back cache by default. Turning off the write cache makes them 
> really slow. SCSI disks usually have write-back caches off by 
> default, but there are tools to turn it on. The lack of write-back 
> cache on SCSI is not that bad, because there's an efficient way to 
> queue multiple commands to the disk
> (wich can be seen as write-back with write notification).
> 
> So: with IDE disks not much more can be done than what is acually 
> done, without serious performances loss. SCSI disks are safe,
>  provided the defaults didn't get changed on the disk (and the disk 
> has safe defaults).
> 
> I've seen fsck fail on occasion on systems with IDE disks, but never 
> with SCSI disks (exept because of hardware failure).
> 
> -- 
> Manuel Bouyer <bouyer@antioche.eu.org>
>      NetBSD: 24 ans d'experience feront toujours la difference
> --