The window/process that is causing the problem can be located by using the ps(1) command (auxw options might be necessary). The process can then be killed. Eliminate the console window running with -C, and control returns to the real console.
Machine hung in reboot process: when the user is booting the machine, it hangs at checking file systems.
As a possible workaround, do the following:
Boot miniroot from tape or CD-ROM.
Type: mkdir mnt.
Mount the root partition to some mount point (/mnt).
Change the directory to /mnt/dev.
Make sure the console is located in the mnt/dev directory.
If not, make the device std (MAKEDEV std).
Halt the system and reboot.