On Mon, Dec 20, 2010 at 11:50:21AM +0100, Andreas Bartelt wrote:
> On 12/19/10 22:28, Kenneth R Westerback wrote:
> ...
> >You should NEVER use 'c' partition. Amoung other things, it is
> >always set by the kernel to encompass the whole disk, everytime the
> >disklabel is read. If you restore to a different sized disk interesting
> >things might happen. I thought we also always set it to UNUSED, but
> >if not I will revisit that.
> >
>
> I've used the native disk sd4c as RAID only for testing, since this
> improved my understanding of the problem.
>
> Is there also a problem when newfs is used on the virtual
> softraid(4) disk 'c' partition (rsd5c in my example)?
>
> I originally discovered the problem when I tried newfs(8) on rsd5c
> where the native disk was sd4a. As I wrote in my initial mail, this
> results in a kernel panic. The kernel panics in
> sr_crypto_finish_io(), and before this, bounds_check_with_label (in
> kern/subr_disk.c) (which gets called in sd.c:572 for the softraid(4)
> disk sd5) returns '-1'. I didn't further inspect if this panic
> could/should be avoided like in the test where the native RAID disk
> was sd4c.
>
The same issue ('c' being set by kernel) will apply to softraid
devices too. You seem to have discovered a bug, so your test process
was good from that standpoint. :-). But you shouldn't use 'c' for
a filesystem or RAID.
.... Ken
