Subject: bad144, esdi & such
To: None <port-i386@netbsd.org>
From: Frank van der Linden <vdlinden@fwi.uva.nl>
List: port-i386
Date: 11/17/1994 12:28:49
I've installed (upgraded from 0.9a) 1.0 on the gateway/fileserver for
our local pc-net here. Data on the machine:
486 DX/33
64Mb internal memory
Micropolis 1518-15 ESDI disk (1.2Gb formatted, 2100 cyl, 15 heads, 83 sectors)
Ultrastor-12 ESDI controller
2x WD8013EP, 2 serial ports, one 1.44 floppy drive
Now, the disk is getting a little bit old, so bad spots are popping up.
I low-level formatted the thing to use one spare sector per track. So that
leaves 82 sectors for data. I have to do this, if I don't you can't get much
done on the thing. The NetBSD install lets me specify the 82 sectors in stead
of the 83, so far so good.
Because of the many bad spots, I thought it'd be a good idea to do bad144
bad sector mapping. So I replied 'no' to the question if it had automatic
bad sector forwarding. However, this always leads to hard errors when
setting up the bad144 table: it is _always_ (no matter how many cylinders
I use for NetBSD) unable to write/read things from track (NetBSDcyls - 1),
head 14. It always produces hard errors doing that. I wonder if the bad144
handling in wd.c uses the original (83 sector) format, as still returned
by the controller, not the info from the disklabel. I haven't had much time
to look into the driver.
Another problem with it is, that the machine sometimes crashes, apparently
doing disk I/O. This can happen twice a day, or once in 40 days.. very
irregular. I had this once since I upgraded to 1.0. I was never sure whether
this was due to bad spots, or the wd driver somehow fighting with the old
ESDI disk/controller. Usually there are some files producing 'bad file
descriptor' after such a crash. Mainly in the upper part of the disk
(which is where the Linux files are stored; 4 Linux clients use the NFS server,
there is one NetBSD client.. never had trouble in the NetBSD /usr part which
I NFS mount on there).
Anyway. The disk is going to be replaced with an SCSI disk in the next week,
so there's not much time to test (although, I could put it in the NetBSD
client after that.. oh no, the damn thing is so big that it won't fit ;))
Which brings me to another point: the machine has 64Mb memory, it's an ISA,
and it's going to have a SCSI installed in it.. Yep, can't use NetBSD then :(
Since I am surrounded by Linux fanatics here, it's probably going to
run Linux. I won't start any religious things here, but: I'll be depending
on Linux as a fileserver and gateway? Oh no! Let's just say that I have, uhm,
vivid memories of the previous time I used Linux for that sort of thing.
So, here's my desperate plea: does anyone have bounce buffer patches
lying around? Please? I don't mind if they're ugly.. just as long as they
have been moderately tested. I'd pull 'em out of FreeBSD myself, but I have
nothing to test them on (and I can't start making such patches to the kernel
of a fileserver when it is needed). Many many thanks in advance.
- Frank