On Sun, Apr 23, 2000 at 02:48:05AM -0700, Todd Whitesel wrote:
> > Guess I screwed it... Just got lucky the previous 100 times or so that I
> > have done something similar ;)
> 
> If there is a safe way to do this, it usually involves Stop-A'ing the
> kernel so there won't be any activity on the SCSI bus _while_ you're
> changing the connectors around, and then continuing it when you're done.
> (It's also a good idea to let the machine get quiet and sync it first.)

I'm not sure all controllers can do this but the ncr53c8xx can put its SCSI
lines in high-impedence by register settings. A ioctl which could hang
the scsi controller and disconnect it from the SCSI bus for a while
would allow this kind of this in a safe way (I think the stop-A trick may
have bad side effect if you halt the kernel in the middle of a
disconnect/reselect transfer).

> 
> I used to do this all the time with SunOS back in the mid-90's and it
> worked great. Then solaris came along and introduced "boot -r" (aiee!!)
> and suddenly it became a royal pain in the ass to share our scarce Sun
> CD-ROMs and tape drives...

I ran into this as well, ended up in plug the tape drive on a SunOS4 box.
Tried playing with drvconfig & all but none worked ... but it's off-topic :)

--
Manuel Bouyer <bouyer@antioche.eu.org>
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