Subject: Re: Bad sector troubles.
To: Boris Gjenero <email@example.com>
From: Anders Magnusson <firstname.lastname@example.org>
Date: 03/11/1997 20:39:47
> Hmm... I doubt it. Take a look at the disktab for an RD53 on MSCP:
> Now here are the actual specs for the RD53 which are used for the MFM
> 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?
No, the driver does not use any sector replacement. If I understand
the Ultrix sdc manual page correct, then bad block replacement are done
in hardware on MVII/MSCP, and software on MV2000. I haven't the slightest
idea of how this should be done...
> 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
You can try; it depends of if bad blocks are remapped by the software
or hardware. ``You cannot more than fail''.