Yes, that's the case. 
You can do the link from another guest thing as Mike describes or boot a rescue 
system (your installation media).

And put this in /etc/inittab if you want the behavior where it is not prompted:

1:2345:respawn:/bin/bash -i




-----Original Message-----
From: Linux on 390 Port [mailto:[email protected]] On Behalf Of Michael 
MacIsaac
Sent: Thursday, February 19, 2015 8:06 AM
To: [email protected]
Subject: Re: [LINUX-390] Single User mode Linux Guest

Jake,

Which Linux are you using?

I tried on SLES, but could not get logged in as root without the password.
In "The Virt'n Cookbook" section 26.1.1 "Enter single user mode", it states:
    "In single user mode, you are logged in as the root user."

But this does not seem to be the case (who wrote that book? - somebody better 
fix it :))

What I see is a prompt for the root password:

 INIT: Going single user
 INIT: Sending processes the TERM signal *Give root password* for maintenance  
(or type Control-D to continue):

My next approach would be to link to the disk with the root file system R/W, 
mount it, and chroot to it. Do you have another Linux system you can use?  
Here's an example of modifying the root password on LINUX138 which as a 100 
minidisk as the root file system (this virtual machine has OPTION LNKNOPAS so I 
am not prompted for the MR password on the LINK command):

# *vmcp link linux138 100 1100 mr*
# *chccwdev -e 1100*
Setting device 0.0.1100 online
Done
# *lsdasd*
Bus-ID     Status      Name      Device  Type  BlkSz  Size      Blocks
==============================================================================
0.0.0100   active      dasda     94:0    ECKD  4096   7042MB    1802880
0.0.0101   active      dasdb     94:4    ECKD  4096   7042MB    1802880
0.0.*1100   *active      *dasde     *94:16   ECKD  4096   7042MB    1802880
# *ls /mnt*
# *mount /dev/dasde1 /mnt*
# *chroot /mnt*
# *passwd root*
Changing password for user root.
New password:
BAD PASSWORD: The password is shorter than 8 characters Retype new password:
passwd: all authentication tokens updated successfully.
# *exit*
# *umount /mnt*
# *vmcp det 1100*
DASD 1100 DETACHED
HTH.

    -Mike

On Thu, Feb 19, 2015 at 10:42 AM, Veencamp, Jonathon D. < 
[email protected]> wrote:

> And single user mode puts you right into root without password, 
> because it's assumed if you control the console, then you must be ok.  
> (control your consoles everyone!)
>
> Have I got that right?
>
> -----Original Message-----
> From: Linux on 390 Port [mailto:[email protected]] On Behalf Of 
> Bruce Hayden
> Sent: Thursday, February 19, 2015 9:39 AM
> To: [email protected]
> Subject: Re: Single User mode Linux Guest
>
> Enter:  passwd root
>
> root can change any password without knowing the existing one - even 
> its own..
>
>
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