Hexediting on a unmountable filesystem?
Hello list. Complicated question: I have a old SGI box with an installed IRIX 5.something, that i got for free a while back. Problem: No root passsword. Only "Guest" account access. Linux cant read the older 5.x XFS system Thus having an unmountable filesystem. So i can't mount it and change the password manually. Question: Can i somehow find the exact place on any given disc for a file, and hexedit the "device" and thereby changing it? (In this case; the entry for root in /etc/password) I know i can get the IRIX media for almost nothing, but i see this as an opportunity to delve deeper into security issues... -- /Rikard ----------------------------------------------------------------------------- email : rikard.j@rikjoh.com web : http://www.rikjoh.com mob : +46 (0)736 19 76 25 ------------------------ Public PGP fingerprint ---------------------------- < 15 28 DF 78 67 98 B2 16 1F D3 FD C5 59 D4 B6 78 46 1C EE 56 >
Hello list. Complicated question:
I have a old SGI box with an installed IRIX 5.something, that i got for free a while back.
Problem: No root passsword. Only "Guest" account access. Linux cant read the older 5.x XFS system Thus having an unmountable filesystem. So i can't mount it and change the password manually.
Question: Can i somehow find the exact place on any given disc for a file, and hexedit the "device" and thereby changing it? (In this case; the entry for root in /etc/password)
I know i can get the IRIX media for almost nothing, but i see this as an opportunity to delve deeper into security issues...
-- /Rikard
----------------------------------------------------------------------------- email : rikard.j@rikjoh.com web : http://www.rikjoh.com mob : +46 (0)736 19 76 25 ------------------------ Public PGP fingerprint ---------------------------- < 15 28 DF 78 67 98 B2 16 1F D3 FD C5 59 D4 B6 78 46 1C EE 56 >
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Hi, I used dd to copy files from an unmountable disc (due to a fs-crash). As far as I've seen, all offset parameter exist for input as well as for output so you should be able to use it for writing on unmountable discs as well. You just take /dev/hdxyz as a file, not as a device Another try might be to use xfs utils. I haven't got any xfs but for JFS there is a jfs_debugfs which is very comfortable. 'apropos xfs' pointed to xfs_db. According to it's man page, it might be an equally useful tool. But I'd check the differences between your old XFS and newer XFS before using a new tool on an old version. ('http://oss.sgi.com/projects/xfs/' might help.)
Hello, Am Samstag, 14. Januar 2006 01:41 schrieb Rikard Johnels:
I have a old SGI box with an installed IRIX 5.something, that i got for free a while back.
Problem: No root passsword. Only "Guest" account access. Linux cant read the older 5.x XFS system Thus having an unmountable filesystem. So i can't mount it and change the password manually.
Question: Can i somehow find the exact place on any given disc for a file, and hexedit the "device" and thereby changing it? (In this case; the entry for root in /etc/password)
Can you do something similar to init=/bin/bash on boot prompt? Just a wild guess, since I don't know anything about IRIX. Oh, hexediting a filesystem is something I do _not_ recommend ;-) Regards, Christian Boltz -- Hier wird wohl im Moment alles gesiggt, was bei drei nicht auf dem Baum ist. [Thilo Machotta in dag°]
Rikard Johnels wrote:
Hello list. Complicated question:
I have a old SGI box with an installed IRIX 5.something, that i got for free a while back.
Problem: No root passsword. Only "Guest" account access. Linux cant read the older 5.x XFS system Thus having an unmountable filesystem. So i can't mount it and change the password manually.
I used to maintain IRIX systems and it sounds like you've got IRIX 5.2 or 5.3. The native filesystem was efs; don't think xfs appeared until IRIX 6.X. In your situation, I'd start an installation from the installation media, enter a root shell and blank out the root password. I haven't seen IRIX 5.X installation media for a *long* time. One thing you can try to is boot to single user mode, but I'm pretty sure IRIX will prompt for the root password. I can't remember. The steps to boot into single user mode depend on the version of the PROM. Turn the machine on and hit the <ESC> key multiple times to interrupt the boot cycle. You should see a menu system which allows you to "Enter the Command prompt" (or similar). This will put you in PROM mode where the prompt is ">>". At the prompt, type the word "single" and press Enter. If the PROM indicates that it is an unknown command, try the following command sequence instead:
boot sash: boot initstate=s
where ">>" and "sash:" are command prompts. If you're lucky, IRIX will drop you into a single user root shell. Otherwise, it will prompt for the root password. If you don't care about the contents of the disk, your best bet is to perform a fresh installation. I've got an SGI Indy at home with IRIX 6.5.22 installed and it works fine. Your only problem is getting a copy of the installation media. Should you need help performing the installation, take a look at the docs at techpub.sgi.com or let me know. Good luck
participants (4)
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Christian Boltz -
Mark Andrews -
Rikard Johnels -
Simon Hoerder