SCO UNIX system "root password" lost processing

In important computer applications, UNIX systems play a leading role. UNIX has strong scalability, robustness, full support for the Internet and a good user interface, which is not possible and replaced by other non-UNIX systems. At present, UNIX covers most banking, telecommunications, insurance, securities, railway and other system applications. Even in Internet applications, most of them are used by various computer manufacturers to provide various UNIX systems. It can be said that UNIX is everywhere.

SCO's SCO UNIX series products account for a large proportion of the global market share. Because SCO UNIX does not depend on any hardware platform, it can run on personal computers and network systems based on Intel chips. Therefore, it has the characteristics of low cost and easy maintenance, and is well received and welcomed by users.

In China, SCO UNIX is used in the business locations of various commercial banks, insurance companies, post and telecommunications industries. SCO UNIX is quite stable and has low requirements on system hardware. Therefore, it has always been favored by relevant financial departments in China.

The reliability of SCO UNIX itself is quite high, and there are few problems, but human operation sometimes causes some troubles or even fatal problems. One of them is root root users for various reasons. The password is invalid (because the password has been forgotten for a period of time or has been intentionally or unintentionally modified by someone who knows the password). Once this happens, the consequences are very serious: it is impossible to install new software or hardware devices, you can't make any modifications to the parameters of the existing hardware devices, you can't manage the users, and some must use superuser privileges. The programs and commands that are running will also be unusable, and all system management work will be paralyzed. When this happens, it can usually only be solved by reinstalling the system. But in this case, it is possible to lose some important programs and data (because many files may not have access, so they cannot be backed up); second, it takes a considerable amount of time to reinstall the system and debug the application (many applications) There are a lot of random parameters that need to be adjusted on a case-by-case basis, especially for applications that involve communication, so this is just a way to do it. I have found many simpler and more effective solutions through many experiments in my work. I have compiled them for your reference. This method can easily solve the above problems, and can retain all applications and their related parameters. The following work is all implemented on SCO UNIX5.0.5, other versions of SCO UNIX are basically the same, only some differences in some details.

Assuming that a machine root user password has been forgotten, call it A machine; find a machine with the same SCO UNIX 5.0.5 system and know the root user password, call it B machine In addition, two 1.44M 3-inch floppy disks are required, which are marked with BOOT and ROOT, respectively, for making emergency disks. ;

First, check in as root user on machine B, use mkdev fd command, the screen displays:;
1.Filesystem
2.Emergency Boot and Root floppy filesystems
Enter an option or q to quit: Enter 2 and press Enter. The screen displays:
1.96tpi, double sided, 15 sectors per track(1.2Mb 5.25 inch)
2.135tpi, double sided,18 sectors per track(1.44Mb 3.5 inch
3.135tpi, double sided, 36 sectors per track(2.88Mb 3.5 inch)
Enter an option or q to quit: Enter 2 and press Enter, the screen displays:
1.Root filesystem
2.Boot filesystem
3.Single floppy Boot and Root filesystem(2.88Mb only)
If you have high density(1.44M)disks,you must create separate rootand boot filesystem floppies.The root floppy must be prepared first .If you have extra density(2.88Mb)disks, you can choose to have both the root and boot filesystems on the same floppy disk.
Enter an option or q to quit:;

Insert the floppy disk with ROOT into the drive, then enter 1 and press Enter. The intermediate program will ask some questions, all of which answer "Y". After the ROOT disk is finished, the program will return to this screen, then take out the ROOT disk, insert the floppy disk marked with BOOT, input 2 and press Enter, the screen displays:;

1.System specific boot
2.Generic boot(builds a special kernel)The System specific boot floppy can only boot the machine it was created on.
The Generic boot folppy can be used to boot any machine.
Enter an option or q to quit :;

Enter 2 and press Enter. The intermediate program will also ask some questions, and all of them will answer “Y”. When finished, remove the disk, type "q" and press Enter to exit. ;

Second, still on the B machine, insert the ROOT disk into the drive, then enter the following commands in order:;
mount /dev/fd0135ds18 /mnt
cp /etc/passwd /mnt/Passwd
cp /etc/shadow /mnt/shadow
cp /tcb/files/auth/r/root /mnt/root
cd
umount /dev/fd135ds18;

After completing the above commands, remove the disk and the emergency disk is created. ;

Third, insert the BOOT disk into the drive of the A machine, and modify the BIOS parameters of the A machine to make the machine boot from the A drive.
When the “BOOT;” prompt appears, press the Enter key until the machine prompts you to insert the ROOT disk, then remove the BOOT disk, insert the ROOT disk and press Enter until the “#” prompt appears. Then enter the following command:;

mount /dev/hd0root /mnt
mount /dev/fd0135ds18 /tmp
cp /tmp/passwd /mnt/etc/passwd
cp /tmp /shadow /mnt/etc/shadow
cp /tmp/root /mnt/tcb/files/auth/r/root
cd
umount /dev/fd0135ds18
umount /dev/hd0root; Br>

Fourth, remove the floppy disk from the A machine, restart the A machine, and change the BIOS to boot from the hard disk.
When the machine enters the check-in screen normally, the root user password can be used to log in to the root user. ;

After the above steps, the root user password can be completely resolved.

The current SCO UNIX system is widely used in banking, telecommunications, insurance, securities, railway and other industries. The programs and data stored in all machines are quite important. The integrity of the data must be fully ensured when any processing is performed on the machine. If the data is damaged or lost, the consequences will be catastrophic; in addition, if the machine used in these places has any accidents, the repair time allowed is very limited. Therefore, all repair work must be completed in a very short time. The method described in this paper is convenient, fast and safe to implement, and fully meets the above requirements, so it is an effective method to deal with the failure of the root user password. ;