Re: kern/53861: regular kernel panic (ffs_blkfree: bad size)

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Sun, Jan 13, 2019 at 01:25:00PM +0000, Dima Veselov wrote:
> The following reply was made to PR kern/53861; it has been noted by GNATS.
> 
> From: Dima Veselov <kab00m%labma.ru@localhost>
> To: gnats-bugs%NetBSD.org@localhost
> Cc: 
> Subject: Re: kern/53861: regular kernel panic (ffs_blkfree: bad size)
> Date: Sun, 13 Jan 2019 16:22:08 +0300
> 
>  I did and fsck found some errors. More than that - I had to check
>  big partition (more than 5Tb) twice, because first run failed 
>  overwhelming with "Can't read sectors" error showing negative
>  block numbers.
>  
>  It appears bug should be closed, however I am still very concerned
>  about using log filesystem in production.  Isn't that a stuation, 
>  which should be prevented by log?

Not in all case; only if the unclean shutdown if from an external cause (e.g.
power loss). I've seen this kind of issue with different log filesystems, and
linux sets a flag on disk when it runs into a filesystem inconsistency
to force fsck on next reboot.

>  
>  Also, by the way - can it be a cause if I add 'log' to fstab first time
>  and then server reboots thinking it has a log, but leaving unclean
>  partition in fact?

no, fsck is skipped only if the log actually exists on disk.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--