Red Hat Enterprise Solaris vs Linux Run Levels
It's the little things... Why does trying to power off a Linux box using "init 5" fail? Ahhh, RHEL uses different run levels! Gotta keep 'em straight!
Solaris Run Levels:
Run level 0 orderly shut down to "OBP" (OK) prompt
Run level 1 single-user/Administrative mode - user logins disabled
Run level s single-user/Administrative mode - user logins disabled
Run Level S single-user/Administrative mode - user logins disabled
Run level 2 multi-user mode with no NFS
Run level 3 multi-user mode with networking (default)
Run level 4 not used
Run level 5 shut down & power off
Run level 6 full shutdown and reboot (graceful shutdown & reboot)
Linux Run Levels:
Run level 0 orderly shut down and power down
Run level 1 single-user mode
Run level s single-user mode
Run level S single-user mode
Run level 2 multi-user mode with networking support, but no network services(i.e., X-Windows support, NFS/NIS, at, or xinetd support)
Run level 3 multi-user mode with networking support, plus network services
Run level 4 not defined
Run level 5 multi-user mode with X-Windows support (default run level)
Run level 6 full shutdown and reboot (graceful shutdown & reboot)
Run level 7,8,9 not defined
RHEL also has a "poweroff" command that performs the same function as "init 5" on Solaris, or "init 0" on RHEL. However, just remember to put the word "man" in front of that "poweroff" command if you're doing research on it, since the RHEL "poweroff" command works A LOT faster than the Solaris "init 5" command - there's no "quick, kill the process" option to keep the system from going down immediately when you enter "poweroff" in error!!! :-)
Solaris Run Levels:
Run level 0 orderly shut down to "OBP" (OK) prompt
Run level 1 single-user/Administrative mode - user logins disabled
Run level s single-user/Administrative mode - user logins disabled
Run Level S single-user/Administrative mode - user logins disabled
Run level 2 multi-user mode with no NFS
Run level 3 multi-user mode with networking (default)
Run level 4 not used
Run level 5 shut down & power off
Run level 6 full shutdown and reboot (graceful shutdown & reboot)
Linux Run Levels:
Run level 0 orderly shut down and power down
Run level 1 single-user mode
Run level s single-user mode
Run level S single-user mode
Run level 2 multi-user mode with networking support, but no network services(i.e., X-Windows support, NFS/NIS, at, or xinetd support)
Run level 3 multi-user mode with networking support, plus network services
Run level 4 not defined
Run level 5 multi-user mode with X-Windows support (default run level)
Run level 6 full shutdown and reboot (graceful shutdown & reboot)
Run level 7,8,9 not defined
RHEL also has a "poweroff" command that performs the same function as "init 5" on Solaris, or "init 0" on RHEL. However, just remember to put the word "man" in front of that "poweroff" command if you're doing research on it, since the RHEL "poweroff" command works A LOT faster than the Solaris "init 5" command - there's no "quick, kill the process" option to keep the system from going down immediately when you enter "poweroff" in error!!! :-)
