| RC(8) | System Manager's Manual | RC(8) |
rc, rc.firsttime,
rc.local, rc.securelevel
— command scripts for system startup
rc is the command script that is invoked
by init(8) when the system starts up. It
performs system housekeeping chores and starts up system daemons.
Additionally, rc is intricately tied to the
netstart(8) script, which runs commands
and daemons pertaining to the network. rc is also
used to execute any rc.d(8) scripts defined
in rc.conf.local(8). The
rc.securelevel,
rc.firsttime, and rc.local
scripts hold commands which are pertinent only to a specific site.
All of these startup scripts are controlled to some extent by variables defined in rc.conf(8), which specify which daemons and services to run.
Before init(8) starts
rc, it sets the process priority, umask, and
resource limits according to the “daemon” login class as
described in login.conf(5). It then
starts rc and attempts to execute the sequence of
commands therein.
The first part of rc runs an
fsck(8) with option
-p to “preen” all disks of minor
inconsistencies resulting from the last system shutdown and to check for
serious inconsistencies caused by hardware or software failure. If this
auto-check and repair succeeds, then the second part of
rc is run. However, if the file
/fastboot exists, fsck will not be invoked. The file
is then removed so that fsck will be run on subsequent boots.
The second part of rc then asks
rc.conf(8) for configuration variables,
mounts filesystems, saves dmesg(8) output
to the file /var/run/dmesg.boot, starts system
daemons, preserves editor files, clears the scratch directory
/tmp, uses
savecore(8) to save any possible core
image that might have been generated as a result of a system crash, and
relinks kernel objects in a random order.
If at any point the boot script fails,
init(8) enters single-user mode, allowing
the superuser a shell on the console. On exiting this mode, init again
invokes rc, but this time without performing the
file system preen.
Before rc starts most system daemons,
netstart(8) is executed.
rc.securelevel is executed by
rc to start daemons that must be run before the
security level changes. Following this, rc then sets
the security level to '1' if it wasn't set already by
rc.securelevel. See
securelevel(7) for the effects of
setting the security level.
If rc.firsttime exists, it is executed
once and then deleted. Any output is mailed to root.
rc.local is executed towards the end of
rc (it is not the very last as there are a few
services that must be started at the very end). Normally,
rc.local contains commands and daemons that are not
part of the stock installation.
rc not to run
fsck(8) during the next boot.rc at boot time.sysctl.conf(5), securelevel(7), init(8), netstart(8), rc.conf(8), rc.d(8), rc.shutdown(8), rcctl(8)
The rc command appeared in
4.0BSD.
| February 10, 2020 | OpenBSD-current |