Forgotten password - red hat

empirix

I installed Red hat 7 on an old pc and i have stupidly forgotten my password or it could even be my uisername i forgot.

Anyways, is there any way around this without having to reload the system. The pc isn't on a network or anything and its really just a standard install of red hat.

I heard something about getting a command line up at the Grub screen by pressing a short cut key and going from there. Does anybody out there know anything about this.

davej

You may or may not be running a boot loader. Anyway at the boot prompt type 'linux single'. This will boot you into single user mode. Now open the /etc/shadow file and remove the (encrypted) password on the line that begins with "root:xxxxx:" (leave the colons though).


Now reboot as normal. There should now be no password set on the root a/c.
(In fact you are probably better running passwd once you have deleted the old entry)


davej

maxheadroom

or, if you can't manage to start your linux system, knoppix will allow you to do the same thing as davej suggested.

longword

Originally posted by empirix
I heard something about getting a command line up at the Grub screen by pressing a short cut key and going from there. Does anybody out there know anything about this.

Single user mode is what you're after, and you get that by adding the option 'single' to your boot command in GRUB. I'm not sure about older versions of grub but I think it's 'a' to append an option to your boot, then 'b' to go with that. Then set the password with 'passwd'. There's no need to edit the files by hand.

empirix

Lads thanks for that info will give it a go when i get home.

I'm not sure whether i get a boot command prompt in Grub(thats my problem), although its been a while and to say my knowledge of Linux now is hazy, is an understatement.
Anyway thanks for the advice, its vmuch appreciated

fractal

You do indeed get a boot command promt in Grub...

When you get to the grub menu just hit 'e' and it will allow you to edit the command line of the currently select kernel..

Also if the 'single' parameter doesnt work you can try.. passing 'init=1' to the kernel too.. That should also give you single user mode..

Happy cracking..

niallb

Hi,
'init=1' will fail, but just because it's two ideas run together.
Press 'e' to get to edit mode on the line, and add just the number 1.
This requests a boot to runlevel 1.
That might still ask for a password.
If it does, start again and type in init=/bin/bash
This will give you a prompt with no password.

It'll also leave your root partition mounted readonly so you can't do anything.
You can get around this by typing
mount -n -o remount,rw / (The -n means don't try to update the mtab file - it can't yet)

Now try to edit /etc/shadow with your favourite editor,
you should get in.
Remove everything between the first two colons after the word root (i.e. root::blah:blah)
Type sync a few times before logging out.
You're running bash instead of init, so there's nothing to shut down the system cleanly.

Best of luck,
NiallB

Capt'n Midnight

This wouldn't have happened if you had used windows.

Let that be a warning to you !

niallb

Ever gone through the procedure for recovering a lost
Windows administrator password?

empirix

This worked below: cheers for everything lads!

Originally posted by niallb
Hi,
'init=1' will fail, but just because it's two ideas run together.
Press 'e' to get to edit mode on the line, and add just the number 1.
This requests a boot to runlevel 1.
That might still ask for a password.
If it does, start again and type in init=/bin/bash
This will give you a prompt with no password.

It'll also leave your root partition mounted readonly so you can't do anything.
You can get around this by typing
mount -n -o remount,rw / (The -n means don't try to update the mtab file - it can't yet)

Now try to edit /etc/shadow with your favourite editor,
you should get in.
Remove everything between the first two colons after the word root (i.e. root::blah:blah)
Type sync a few times before logging out.
You're running bash instead of init, so there's nothing to shut down the system cleanly.

Best of luck,
NiallB

Capt'n Midnight

Originally posted by niallb
Ever gone through the procedure for recovering a lost
Windows administrator password?

Always wanted to try the one when you rename commandprompt.exe to defautlscreensavername.scr and wait 15 minutes for the logon screen saver to appear.

electrofelix

Originally posted by niallb
Ever gone through the procedure for recovering a lost
Windows administrator password?

grab the Change NT Password Utility from the net, burn to CD if you need the extra drivers. Reboot machine, insert CD and follow the screen instructions to reset the admin password or any other local account password.

Reboot and wola! new password for Administrator account. Works for NT, 2K & XP.

niallb

Exactly,
Step 1) Reboot in linux