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reboot(8) [bsd man page]

REBOOT(8)						      System Manager's Manual							 REBOOT(8)

NAME
reboot - stopping and restarting the system SYNOPSIS
/sbin/reboot [ -lqnhdarsfRD ] /sbin/halt [ -lqndars ] /sbin/fastboot [ -lqndarsRD ] DESCRIPTION
2.11BSD is started by placing it in memory at location zero and transferring to its entry point. Since the system is not reentrant, it is necessary to read it in from disk or tape each time it is to be boot strapped. Rebooting a running system: When the system is running and a reboot is desired, shutdown(8) is normally used to stop time sharing and put the system into single user mode. If there are no users then /sbin/reboot can be used without shutting the system down first. Reboot normally causes the disks to be synced and allows the system to perform other shutdown activities such as resynchronizing hardware time-of-day clocks. A multi-user reboot (as described below) is then initiated. This causes a system to be booted and an automatic disk check to be performed. If all this succeeds without incident, the system is then brought up for multi-user operation. Options to reboot are: -l Don't try to tell syslogd(8) what's about to happen. -q Reboot quickly and ungracefully, without shutting down running processes first. -n Don't sync before rebooting. This can be used if a disk or the processor is on fire. -h Don't reboot, simply halt the processor. -d Dump memory onto the dump device, usually part of swap, before rebooting. The dump is done in the same way as after a panic. -a Have the system booter ask for the name of the system to be booted, rather than immediately booting the default system (/unix). -r Mount the root file system as read only when the system reboots. This is not supported by the kernel in 2.11BSD. -s Don't enter multi-user mode after system has rebooted - stay in single user mode. -f Fast reboot. Omit the automatic file system consistency check when the system reboots and goes multi-user. This is accomplished by passing a fast reboot flag on to the rebooting kernel. This currently prevents the use of -f flag in conjunction with the -h (halt) flag. -D Set the autoconfig(8) debug flag. This is normally not used unless one is debugging the autoconfig program. -R Tells the kernel to use the compiled in root device. Normally the system uses the device from which it was booted as the root/swap/pipe/dump device. Reboot normally places a shutdown record in the login accounting file /usr/adm/wtmp. This is inhibited if the -q or -n options are present. Note that the -f (fast reboot) and -n (don't sync) options are contradictory; the request for a fast reboot is ignored in this case. Halt and fastboot are synonymous with ``reboot -h'' and ``reboot -f'', respectively. Power fail and crash recovery: Normally, the system will reboot itself at power-up or after crashes if the contents of low memory are intact. An automatic consistency check of the file systems will be performed, and unless this fails, the system will resume multi-user operations. SEE ALSO
autoconfig(8), sync(2), utmp(8), shutdown(8), syslogd(8) 3rd Berkeley Distribution May 24, 1996 REBOOT(8)

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REBOOT(8)						    BSD System Manager's Manual 						 REBOOT(8)

NAME
reboot, halt, fastboot, fasthalt -- stopping and restarting the system SYNOPSIS
halt [-lnpq] [-k kernel] reboot [-dlnpq] [-k kernel] fasthalt [-lnpq] [-k kernel] fastboot [-dlnpq] [-k kernel] DESCRIPTION
The halt and reboot utilities flush the file system cache to disk, send all running processes a SIGTERM (and subsequently a SIGKILL) and, respectively, halt or restart the system. The action is logged, including entering a shutdown record into the user accounting database. The options are as follows: -d The system is requested to create a crash dump. This option is supported only when rebooting, and it has no effect unless a dump device has previously been specified with dumpon(8). -k kernel Boot the specified kernel on the next system boot. If the kernel boots successfully, the default kernel will be booted on successive boots, this is a one-shot option. If the boot fails, the system will continue attempting to boot kernel until the boot process is interrupted and a valid kernel booted. This may change in the future. -l The halt or reboot is not logged to the system log. This option is intended for applications such as shutdown(8), that call reboot or halt and log this themselves. -n The file system cache is not flushed. This option should probably not be used. -p The system will turn off the power if it can. If the power down action fails, the system will halt or reboot normally, depending on whether halt or reboot was called. -q The system is halted or restarted quickly and ungracefully, and only the flushing of the file system cache is performed (if the -n option is not specified). This option should probably not be used. The fasthalt and fastboot utilities are nothing more than aliases for the halt and reboot utilities. Normally, the shutdown(8) utility is used when the system needs to be halted or restarted, giving users advance warning of their impending doom and cleanly terminating specific programs. SEE ALSO
getutxent(3), boot(8), dumpon(8), nextboot(8), savecore(8), shutdown(8), sync(8) HISTORY
A reboot utility appeared in Version 6 AT&T UNIX. BSD
October 11, 2010 BSD

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