The system uses bootable ISL utilities to either load the
system from tape or to start the system from disk. The current boot
utilities are START, UPDATE, INSTALL, and DUMP. There are additional utilities for system management: SADPATCH, DISCUTIL, CLKUTIL, and SAT.
The START utility starts the system from disk. Use this
utility to recover from a system hang or failure or to reboot the
system after scheduled downtime.
Bringing in the system from tape is referred to as a system
load. The system uses two utilities to perform a system load, which
builds essential operating system files and data structures on disk.
The two load utilities, UPDATE and INSTALL, have the option to boot the system from disk
once the load operation is complete.
The INSTALL utility completely replaces the contents of the
disk and places the base operating system files, including the system
configuration files, on disk. If you have installed a new system
over an already existing system, you can use the STORE/RESTORE utility to restore the original system dictionary,
other subsystem files, and user files to the new system after the INSTALL is complete.
The UPDATE utility replaces the current base system files
on disk and optionally replaces system configuration files (if you
name a different configuration file when you use the UPDATE utility). If you do not name another configuration
file, the original file will remain after the update.
The base system files contain the copy of the operating system
to be placed on disk. As part of every system, these files make
a minimal or base system. INSTALL and UPDATE utilities, optionally, attempt a software reboot
from disk.
The DUMP utility writes the current state of the system
main memory and secondary storage to tape for analysis. DUMP, also optionally, attempts a software reboot from
disk.
Depending on the utility and the options specified, the system
either halts at the end of the utility's execution or reboots from
disk.
If you want to see a list of command options along with an
explanation of correct usage and default values, enter help at the ISL prompt.