Subject: Re: RAID-1 and crash dumps
To: Greg Oster <oster@cs.usask.ca>
From: Martti Kuparinen <martti.kuparinen@iki.fi>
List: current-users
Date: 02/04/2004 20:10:55
Greg Oster wrote:

> You're wanting to make wd0e "line up" with 'raid0a' (which starts at 
> block 0 of raid0), right?  The "magic value" you're looking for here 
> is "RF_PROTECTED_SECTORS" (defined in <dev/raidframe/raidframevar.h>)
> which is the number of sectors before the "data" part of the RAID set 
> (i.e. before where "block 0" of raid0 would be.)  The value is "64", 
> which means the start of "e" above should be 63+64=127.
> 
> So to get your swap partition lined up, you'll want:
> 
> 16777216+64+63 = 16777343

Thanks, I got it now :-)

# disklabel wd0
  a: 241254657        63       RAID
  c: 241254657        63     unused
  d: 241254720         0     unused
  e:  16777216       127     4.2BSD   2048 16384 27672
  f: 222380160  18874495     4.2BSD   2048 16384 28856

# mount -r /dev/wd0f /mnt
# df
Filesystem  1K-blocks     Used     Avail Capacity  Mounted on
/dev/raid0a   8258270   370958   7474398     4%    /
/dev/wd0f   109465462  7562518  96429670     7%    /mnt

However, Manuel's question about "the old way of computing offsets"
is still open and needs to be described in the handbook. I'll
do it once I understand what's going on here...

Martti