How to recover the hscroot password on an HMC
Posted on Sat, Dec 02, 2023 at 15:01 by Hubertus A. Haniel
We recently where locked out of an old HMC that is no longer supported but had problems with an LPAR attached to it which we are trying to get rid off so IBM where not very helpful to get us into it so I found the below procedure somewhere on the internet and now tested it on V7R7.9.0 before I will do on the real system by installing the HMC code on a VMware system - for that some hacks that are described at http://omnitech.net/reference/2013/05/01/installing-hmc-in-virtualbox/ where necessary I have lost the link to the procedure below so I am putting it here in case somebody else needs it. I did not actually have to follow the full procedure as init=/bin/rcpwsh prompted me to change the hscroot password rather than dropping me into a shell and then continued to fully boot at which stage I could just could log straight back in.
Anybody familiar with Linux will probably be familar with this procedure as it works on most linux distributions with init=/bin/bash. In case of the HMC I just was not sure how locked down these devices where and would I be challanged with encrypted filesystems and stuff like that....
Here we go:
1) Power off the HMC.
2) Power on the HMC, and as soon as the Loading grub message is displayed
quickly press the F1 key to get into grub.
The Grub menu will show one line with the text hmc.
3) On the Grub menu, select e for edit. The next GRUB screen is displayed with two lines:
root (hd0,0)
kernel (hd0,1)/boot/bzImage ro root=/dev/hda2 vga=0x317 apm=power-off
Note: The root device can vary by model: hda2 C03, C04, CR2, and hdc2 for CR3.
4) Move the cursor down to the line starting with kernel. Select e for edit.
Move the cursor to the right and append the following to the end of the string:
V5.1.0 to V6.1.1: init=/bin/bash
V6.1.2 and later: init=/bin/rcpwsh
The final string will vary slightly by version and model:
kernel (hd0,1)/boot/bzImage ro root=/dev/hda2 vga=0x317 apm=power-off init=/bin/rcpwsh
Press the Enter key to save the changes.
5) Press b to boot the changed selection.
This will boot to a bash shell on older HMC's - On newer HMC's this willl prompt you for a new hscroot password after the kernel is loaded and after changing the password it will continue to boot so you can skip the next steps until step 9. You may want to choose a simple password as the keyboard mapping may not match your locale if you are outside the US.
6) Verify root is mounted read/write. If not you may need to rmount it with
mount -o remount,rw /dev/hda2 /
Note: The root device can vary by model: hda2 C03, C04; hdc2 for CR2,CR3; sda2 for CR4.
7) Reset root and hscroot passwords. Run the following commands to reset the passwords. The command will prompt the user to enter the new password and a confirmation password. Any warning concerning the password being too simplistic can be ignored.
Reset root password:
/usr/bin/passwd
Reset hscroot password:
/usr/bin/passwd hscroot
8.) Reboot the HMC (left ctl+left alt+del).
9) Log on as hscroot.
10) Immediately after logon, use the Web-based System Manager (HMC GUI) or the chhmcusr
Edited on: Wed, Mar 13, 2024 15:56Posted in HowTo (RSS), System - AIX (RSS)
