Re: geom_vinum problems (crashes and lockups)

From: Lukas Ertl <le_at_FreeBSD.org>
Date: Sat, 26 Jun 2004 14:07:03 +0200 (CEST)
On Thu, 24 Jun 2004, Daryl Chance wrote:

> for /dev/ad4s1:
> mp3# bsdlabel /dev/ad4s1
> # /dev/ad4s1:
> 8 partitions:
> #        size   offset    fstype   [fsize bsize bps/cpg]
>  c: 60074784        0    unused        0     0
>  d: 60074784        0    4.2BSD     2048 16384 28512

This is a situation that I currently consider 'unsupported'.  The problem 
is that the 'd' partition has no offset, thus it is (from the point of 
view of a geom_vinum drive geom) the same as the 'c' partition.  This is 
the first problem.  The second problem is the on-disk format of a 
bsdlabel.  As far as I understand it, this meta-data is stored inside 
the first partition, so when you open the drive for writing (i.e. 
mount, fsck) you trigger a spoil event which cause all kinds of confusion 
for geom_vinum.

I'm not sure if I find a proper hack for this, so, for now, this is an 
unsupported configuration.  This means that the partition where you want 
to put a vinum drive on _must not_ start at the beginning of a drive and 
has to have an offset, i.e. 16 sectors, as a standard label from 'bsdlabel 
-w' has.

cheers,
le

-- 
Lukas Ertl                         http://homepage.univie.ac.at/l.ertl/
le_at_FreeBSD.org                     http://people.freebsd.org/~le/
Received on Sat Jun 26 2004 - 10:07:56 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:37:59 UTC