Subject: Re: kern/10430: Wd driver cannot handle bad144 table properly?
To: None <firstname.lastname@example.org, email@example.com>
From: Greg A. Woods <firstname.lastname@example.org>
Date: 06/25/2000 12:01:33
[ On Sunday, June 25, 2000 at 22:13:58 (+0900), Takahiro Kambe wrote: ]
> Subject: Re: kern/10430: Wd driver cannot handle bad144 table properly?
> In message <20000625143937.A513@antioche.eu.org>
> on Sun, 25 Jun 2000 14:39:37 +0200,
> Manuel Bouyer <email@example.com> wrote:
> > Then we should port bad144 to SCSI and other supported disk types ?
> I have a adapter which attach an IDE hard disk to SCSI interface.
> It confirms SCSI2 but I don't think SCSI's reassign block command
> works with it.
> So, bad144 might be useful but I also think we might create another
> type of software bad block mapping scheme.
Indeed I have a couple of ESDI-SCSI interfaces (both by Emulex, IIRC,
one 2-LUN unit from a Sun-3, and one 4-LUN unit from a 3B2).
ESDI drives do need manual re-mapping of bad sectors, and IIRC bad144 is
useful to work around a bad sector or two so that you can bridge over to
a time when you can afford to re-format the disk with a new bad-sector
I'm not sure what this means though....
I should also note that I've had some luck with some types of bad
sectors that I can simply gather up into a file I usually call /BAD on
the filesystem. So long as you don't do full low-level dumps of the
disk and you can keep fsck from trying to read them, this is a workable
way of hiding such things.
A generic OS-level bad-block handling tool should not be called bad144
though -- IIRC that name relates directly back to the interface in
ST-506 drives and isn't even correct for ESDI.
I really liked the generic "hdelog" device driver and "hdelogger",
"hdeadd", and "hdefix" programs from AT&T UNIX. Hard disk errors during
normal multi-user mode were automatically caught and logged and often
automatically remapped too.
Greg A. Woods
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