From: smw@alcor.concordia.ca ( Steven Winikoff )
Subject: Re: CD-ROM is really a pseudoterminal??
Summary: Still not working
Organization: Concordia University, Montreal, Quebec
Date: Mon, 16 Nov 1992 23:33:18 GMT

In article <1e6rbhINNig8@ni.umd.edu>, louie@sayshell.umd.edu (Louis A. Mamakos) writes:
> In article <BxMCny.DAw@newsflash.concordia.ca> smw@alcor.concordia.ca ( Steven Winikoff ) writes:
> >I hate to disagree with Boyd Roberts, as he obviously knows what he's
> >talking about (as demonstrated in many other posts to this group,
> >among others). 
> 
> And you shouldn't...

Yes, I understand that now.

I apologize to Boyd, and generally to DEC for my initial doubts about this
issue.

(Of course, I still think that since there are fewer than 255 different
types of devices, there's no *need* to reuse major numbers yet...   and
I still think that doing so is confusing.  Nevertheless, it's not *wrong*,
and I apologize for suggesting that it was.)

 
> >Now *that* is news to me, but then as I mentioned in a previous post, I
> >make no pretensions toward being a kernel hacker.
> 
> It's not really news to anyone with much kernel hacking experience.
> It's been that way since at least V7.

The funny thing is that I'm supposed to know this.  I took a course in
this stuff two years ago, and actually ended up writing some driver
routines for a printer.  It's just that, in the heat of the moment with
my CD-ROM drive refusing to behave, I forgot how this is supposed to
work.


> >I notice that ofiles (which I didn't run yesterday) reports that nobody
> >is using /dev/rz5c, even though pff still finds the telnet process on
> >ptyra.
> 
> Don't worry about the pty; it has nothing to do with your problem.

I now realize that that's true.

 
> >It's definitely not that the mount point directory is busy.  I can't
> >find any other processes using the "real" /dev/rz5c.  So why won't
> >mount do what I want it to do?
> 
> I dunno.. did the CDROM autoconfig when you booted?

Yes.  I just checked the uerf output from the last system boot.  The
relevant excerpts are:

    OS EVENT TYPE                  300.     SYSTEM STARTUP
                                                   ...
    OCCURRED/LOGGED ON                      Mon Oct 26 23:38:40 1992 EST
                                                   ...
                                            rz0 at asc0 slave 0 (RZ58)
                                            rz1 at asc0 slave 1 (RZ58)
                                            rz2 at asc0 slave 2 (RZ58)
                                            rz5 at asc0 slave 5 (RRD42)
                                                   ...


Moreover, in playing around with the drive, the following transcript
occurred:

    root@mercury{596}~: mount -r /dev/rz5c /CD
    ufs_mount: /dev/rz5c on /CD: Mount device busy

    root@mercury{597}~: mount -r /dev/rz5c /mnt
    ufs_mount: /dev/rz5c on /mnt: Mount device busy

    root@mercury{598}~: mount -r /dev/rz5a /mnt
    { HUH?  Why can I mount partition 'a' but not 'c'? }

    root@mercury{599}~: ls -Failsg /mnt
    /mnt/FSA100: No space left on device
    /mnt/UDT430: No space left on device
        ... { many similar messages }

    root@mercury{600}~: umount /dev/rz5a

    root@mercury{601}~: mount -r /dev/rz5a /CD
    ufs_mount: /dev/rz5a on /CD: Mount device busy
    { Even worse!  Why can't I mount *anything* on /CD? }

    root@mercury{602}~: pads /CD
    USER     PID   PPID  CMD         TERM    TYPE  MODE PATH

    root@mercury{603}~: ofiles /CD
    /CD     (directory)
    USER        PID  TYPE    FD  CMD             INODE

    { Hmmm...  /CD sure doesn't *look* busy... }


Now, remember, the disk I'm using is part of the Ultrix Consolidated
Distribution.  There shouldn't be anything strange about it.  Just to
be sure, I tried a different disk (a recent Ultrix On-line Documentation
CD), with *exactly* the same results.

I can mount the 'a' partition, which is interesting but hardly useful,
but it will only mount on some directories and not others.  (Yes, /CD
and /mnt are on the same partition.)

I can't seem to be able to mount the 'c' partition anywhere.

I'm baffled.

    - Steven
________________________________________________________________________
Steven Winikoff      |       smw@         | "I don't want to run the
Software Analyst     | alcor.concordia.ca | world; I merely want to own
Computing Services   |                    | a substantial portion of the
Concordia University | (514) 848-7619     | preferred stock" - Alan Dean
Montreal, QC, Canada | (10:00-18:00 EST)  | Foster,  Cat-A-Lyst
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