Subject: Re: ffs compatibility added, fsck may complain
To: Darrin B. Jewell <>
From: Perry E. Metzger <>
List: current-users
Date: 01/11/2004 18:12:07
"Darrin B. Jewell" <> writes:
> I added the following to src/UPDATING
> 20040109:
>         Compatibility for old ffs superblock layouts has been
>         added, and the restrictive fsck checks have been reenabled
>         when using those layouts.  If you have been using -current
>         since 20030402, you may find that fsck again signals fatal
>         superblock mismatches.  To work around, you can use
>         fsck -b 32 to restore an alternate superblock.

Actually, it is fsck_ffs. I just found that out the hard way hitting
my head against the wall because fsck doesn't have an -b option.

Also, the situation is REALLY unfortunate. It means that you're going
to end up with machines mysteriously failing on people without much
recourse in the field if you don't happen to remember the cure. Also,
people needing to blind upgrade boxes in colos will get screwed -- I'm
one of those.

Is there any way to either get the kernel to fix this for you during
boot, or to provide a way to fix it in advance so that fsck doesn't
fail during reboot? This is actually pretty important.


> See the following message to tech-kern
>  <URL:>
> or pr's port-macppc/23925 and port-macppc/23926 for more details
> See pr 23925 or 23926 for more details
>  <URL:>
>  <URL:>

Perry E. Metzger