Processing of root password loss in SCO Unix system

The UNIX system plays a leading role in the important field of computer application. UNIX is highly scalable, robust, fully supported by the Internet and a good user interface, which is not available and alternative to other non-UNIX systems. Currently, UNIX covers most banking, telecommunications, insurance, securities, railways and other system applications, even in Internet applications, the use of the vast majority of the various computer vendors to provide a variety of UNIX systems, can be said that UNIX is everywhere.

SCO's SCO UNIX products account for a considerable share of the global market. Since SCO UNIX is not dependent on

On any hardware platform, based on Intel's chip PC and network system can be run, so low-cost, easy maintenance features, by the vast number of users and welcome.

In the domestic, the commercial bank's business point, each insurance company, the post and telecommunications industry all uses the SCO UNIX. SCO Unix run fairly stable, the system hardware requirements are not high, so has always been the domestic financial departments of all ages.

SCO UNIX itself is fairly high in reliability and rarely has any problems, but human operations sometimes cause some problems or even fatal issues, one of which is that root Superuser's password is invalidated for a variety of reasons ( Because a period of time did not use to forget the password or other people know the password intentionally or unintentionally modified. Once this happens, the consequences are very serious: it is impossible to install new software or hardware devices, no changes to the parameters of existing hardware devices, no management of users, and some programs and commands that must be run with Superuser privileges will not be available, and all system management will be paralysed. When this happens, it is generally only possible to reinstall the system to resolve it. But this makes it possible to lose some important programs and data (because many files may not have permission to be backed up), and it takes a considerable amount of time to reinstall the system and debug the application (many applications have many random parameters that need to be tailored to the situation, Especially when it comes to communication applications), so this is just a way to do it. I have been in the work after many tests found a more simple and effective solution, now sorted out for your reference. This approach can easily solve the above problems and can preserve all applications and their associated parameters. All of the following work is done on SCO UNIX5.0.5, and other versions of SCO Unix are essentially the same, with only a few differences in some detail.

Suppose a machine root user password is forgotten, call it a machine; find a machine that installs the same SCO UNIX 5.0.5 system and knows the root password, calling it a B-machine, plus 2 1.44M 3-inch floppy disks, labeled Boot and root, to make the emergency disk.

First, in the B machine to the root user check-in, the use of Mkdev FD command:

1.Filesystem

2.Emergency Boot and Root floppy filesystems

Enter an option or Q to quit: Enter 2 and return:

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 a option or Q to quit: Enter 2 and return, the screen shows:

1.Root filesystem

2.Boot filesystem

3.Single floppy Boot and Root filesystem (2.88Mb only)

If you are have high density (1.44M) disks,you must create separate Rootand boot filesystem floppies. The root floppy must be prepared. If you are have extra density (2.88Mb) disks,you can choose to have both the root and boot filesystems on the same disk.

Enter a option or Q to quit:

First insert the floppy disk labeled root into the drive, then enter 1 and return. The intermediate program will do some questioning, all answer "Y" can be. After the root disk is finished, the program will return to the screen, then remove the root disk, insert the floppy disk marked with boot, enter 2 and return, the screen shows:

1.System Specific Boot

2.Generic boot (builds a special kernel) the System specific boot floppy can only boot the machine it being created on.

The Generic boot folppy can be used to boot any machine.

Enter a option or Q to quit:

Input 2 and enter, the intermediary program will also do some questions, the same answer all "Y" can be. When finished, remove the disk, enter "Q" and press ENTER to exit.

Second, still on the B machine, insert the root disk into the drive, and then enter the following 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 command to remove the disk, the emergency disk is finished.

Insert the boot disk into the drive of a machine and modify the BIOS parameters of machine A to enable the machine to boot from a drive. When the "BOOT" prompt appears, press ENTER until the machine prompts you to insert the root disk, then remove the boot disk, insert the root disk, and enter, until the "#" prompt appears. Then enter the following command in turn:

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

Remove the floppy disk from a machine, reboot a machine, and boot the BIOS from the hard drive. When the machine enters the check-in screen normally, the root user password of the B machine can be used for root registration.

The above steps can completely resolve the root user password failure problem.

At present, SCO UNIX system is widely used in banking, telecommunications, insurance, securities, railways and other industries, all the machines stored in the program and data are very important. The integrity of the data should be fully ensured in any processing of the machine, if the data is corrupted or lost, the consequences will be catastrophic, and the machines used in these establishments may have limited repair time if any accidents occur, so all repair work must be done in a very short time. The method introduced in this paper is convenient, fast and safe, and it is in full compliance with the above requirements, so it is an effective method to deal with the root user's password invalidation problem.