Anders Magnusson wrote:
> Test 70 (I think) should rebuild the bad-sector map.

Ouch!  That's a complete reformat.  So there is no non-destructive way? 
It's not too bad now, but what if a new bad sector shows up later. 

> DEC STANDARD 144 bad sector forwarding were used on old disks
> (e.g. Massbus disks). MSCP and MFM disks uses another way, hidden from
> the user. I don't know how it works, and doesn't have any docs for
> it, but the spare sectors are located outside the range accessible from
> normal NetBSD handling. The controller replaces the bad sectors
> automatically without any driver intervention.
> I know this is true for MSCP disks, and I think it works the same way
> on MFM disks.

Hmm...  I doubt it.  Take a look at the disktab for an RD53 on MSCP:
:ns#18:nt#8:nc#963:
18*8*963=138672
Now here are the actual specs for the RD53 which are used for the MFM
device:
Sectors/track:17  Read/write heads:8  Cylinders:1024 
17*8*1024=139264  (592 more sectors, probably replacements on MSCP)
If I actually use the real physical specs in edlabel (as you have to
with the mfm device), then there is no way that some other space for bad
sector replacement could exist.  I'm using the whole drive.  This brings
up two questions:
1 - Does NetBSD even use the bad sector replacement stuff on the VS2000
or does it just write straight to real physical sectors? 
2 - Assuming it does, how do I make sure that it doesn't trash the
replacements?  Should I just reserve 592 sectors at the end of the
drive?

-- 
|  Boris Gjenero <bgjenero@undergrad.math.uwaterloo.ca>              |
|  Home page:  http://www.undergrad.math.uwaterloo.ca/~bgjenero/     |
|  "Luke, you're going to find that many of the truths we cling to   |
|  depend greatly on our own point of view." - Obi-Wan Kenobi, ROTJ  |