Power fail and crash recovery

Normally, the system will reboot itself at power-up or after crashes. An automatic consistency check of the file systems will be performed as described in fsck(8), and unless this fails, the system will resume multi-user operations.

Cold starts

A disk-boot program (/usr/mdec/ufsboot) will attempt to load netbsd from partition A of the boot device, which must currently be an “sd” disk. Alternatively, network boot program (/usr/mdec/netboot) will load netbsd from the NFS root as determined by the procedure described in diskless(8).

Boot program options

-a

Prompt for the root file system device, the system crash dump device, and the path to init(8).

-d

Bring the system up in debug mode. Here it waits for a kernel debugger connect; see ddb(4).

-q

Boot the system in quiet mode.

-s

Bring the system up in single-user mode.

-v

Boot the system in verbose mode.

Any extra flags or arguments, or the <boot string> after the -- separator are passed to the boot PROM. Other flags are currently ignored.

At any time you can break back to the ROM by pressing the ‘L1' and ‘a' keys at the same time (if the console is a serial port the same is achieved by sending a ‘break'). If you do this accidentally you can continue whatever was in progress by typing ‘c' followed by the return key.