[comp.sys.att] 3B2 Horror story - will it ever run?

almquist@cis.udel.edu (Squish) (02/08/91)

From: "Bradley E. Smith" <brad@bradley.bradley.edu>
>Reboot the diskette and instead of 1,2,3 type 'magic mode'. Then select
>the 'shell' option.  This will give you shell access on the floppy.
>you then might be able to mount your root device and edit the password
>file.

WOW!  Att machines are certainly off the beaten track.  You won't find these
funny (or fun?) modes on a Vax or Sun.  Anyways, I go into 'magic mode' and
then select the 'shell' option.  Hurray!  I've got the root prompt it worked.
Could it be my lucky day?  NO!  Nothing exciting is on the 1st disc.  No,
mount, tar, dd, nothing.  Can anyone send me a bootable disc with mount on it.
OR, is there someway that I can copy the contents of one of the other discs
onto the current boot disc with only one disc drive?  This is starting to get
frustrating )-:  Also, I got no responses about the types of tapes I can buy
for my tape drive.  ALSO, the monitor previously advertised is spoken for.
And, finally, I've got two cute AT&T keyboards Serial#362202 L Rd.1983.  Anyone
want these?

- Mike

flint@gistdev.gist.com (Flint Pellett) (02/09/91)

almquist@cis.udel.edu (Squish) writes:

>From: "Bradley E. Smith" <brad@bradley.bradley.edu>
>>Reboot the diskette and instead of 1,2,3 type 'magic mode'. Then select
>>the 'shell' option.  This will give you shell access on the floppy.
>>you then might be able to mount your root device and edit the password
>>file.

>WOW!  Att machines are certainly off the beaten track.  You won't find these
>funny (or fun?) modes on a Vax or Sun.  Anyways, I go into 'magic mode' and
>then select the 'shell' option.  Hurray!  I've got the root prompt it worked.
>Could it be my lucky day?  NO!  Nothing exciting is on the 1st disc.  No,
>mount, tar, dd, nothing.  Can anyone send me a bootable disc with mount on it.

If you want to mount something, you have to do something like this:

# fsck /dev/idsk00
# fsys -m /install /dev/idsk00

(You may not need the file system check fsck.)
That mounts the hard disk's root file system onto the floppy's /install.
You then get an error message that is quite misleading, and should be
ignored- something like /dev/idsk00: no such file or directory.  The
error message apparently comes from not mounting on /mnt (you can't use
/mnt since there isn't one).  Now you have root mounted, and you can get
to some real tools in /install/etc and /install/bin, but it will still
be painful, and you may have to change a lot of env vars as you go to
do stuff.   For example, if you want to use vi you'll quickly find out
that there isn't enough spare space on the floppy in the TMPDIR, etc.
to edit anything of any size.

To unmount, use:

# fsys -u /dev/idsk00

PS: be very careful what you do in situtations like this: if things are
screwed up you can easily make things worse if you don't think about
every move first.  That's probably why AT&T won't advertize this ability,
they don't think most of us peasants in the field know enough to not
mess themselves up worse.  But if you've got something simple to fix
(like a zeroed /etc/passwd file, for example) this can save lots of time.
-- 
Flint Pellett, Global Information Systems Technology, Inc.
1800 Woodfield Drive, Savoy, IL  61874     (217) 352-1165
uunet!gistdev!flint or flint@gistdev.gist.com

rag@genco.bungi.com (Art Gentry) (02/09/91)

In article <44022@nigel.ee.udel.edu> almquist@cis.udel.edu (Squish) writes:
>From: "Bradley E. Smith" <brad@bradley.bradley.edu>
>>Reboot the diskette and instead of 1,2,3 type 'magic mode'. Then select
>>the 'shell' option.  This will give you shell access on the floppy.
>>you then might be able to mount your root device and edit the password
>>file.
>
>WOW!  Att machines are certainly off the beaten track.  You won't find these
>funny (or fun?) modes on a Vax or Sun.  Anyways, I go into 'magic mode' and
>then select the 'shell' option.  Hurray!  I've got the root prompt it worked.
>Could it be my lucky day?  NO!  Nothing exciting is on the 1st disc.  No,
>mount, tar, dd, nothing.  Can anyone send me a bootable disc with mount on it.
>OR, is there someway that I can copy the contents of one of the other discs
>onto the current boot disc with only one disc drive?  This is starting to get
>frustrating )-:  

You need to do a few more things to get where you want to be.

1) do a fsck on root
   /etc/fsck -y /dev/dsk/0s1
2) mount root
   /etc/mount /dev/dsk/0s1 /mnt
3) cd to the hard disc root
   cd /mnt
4) if you want - set your path to reflect the current environment
   PATH=/mnt/bin:/mnt/usr/bin:/mnt/etc:/mnt/usr/lib
   export PATH
5) now you can get to all the files on your hard disc, but remember
   that your 'root' file system is really one level down, 
   ie. / = /mnt
6) do whatever you need to do (ie. edit /mnt/etc/passwd) and then
   unmount the disc
   cd /
   /etc/umount /dev/dsk/0s1
7) sync the disc tables
   sync;sync;sync
8) reboot
   uadmin 2 0

All should be again well with the world, with the exception of the
Middle East.

>Also, I got no responses about the types of tapes I can buy
>for my tape drive. 

Don't know what your original question was, so am making an assumption
that you have a "standard" scsi 60meg tape drive, in which case, I have
had excellent success using 3M DC600HC tapes in mine.

|   R. Arthur Gentry  --  Gentry & Associates -- Excelsior Springs, MO    |
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