Starting and stopping the system

About missing or corrupted system files

On rare occasions, one or more of the critical system files may be accidentally modified or removed, preventing the system from booting or operating correctly. In cases where your system does not boot, you must boot from floppy disks in order to access the system so that you can restore the critical files from backups.

To boot and access a system that does not boot from the hard disk, you must have an emergency boot floppy disk set. This set consists of the boot floppy disk and the root filesystem floppy disk. The boot floppy disk contains three files necessary for booting and loading the UNIX system kernel: /boot, /etc/default/boot, and /unix. The root filesystem floppy disk contains a subset of the UNIX system utilities that you can use to restore your system.

NOTE: We recommend that you have a separate emergency boot floppy disk set for each system or further corruption can result. Systems that have identical hardware and software configurations can share an emergency boot floppy disk set.

If a catastrophic failure occurs and you do not also have a backup of the root filesystem, you must reinstall your SCO system. To do this, follow the instructions for reinitializing the root disk in ``Replacing the root hard disk''.