Server crashed, help..

[forsyth@plan9.cs.york.ac.uk forsyth@plan9.cs.york.ac.uk]

i don't know what you mean by `overwrite the scsi disk' but that
is probably extreme unless things are well and truly curdled.

here are some things to try.  i'm assuming you aren't using a worm jukebox
or pseudo-worm on scsi discs; otherwise what you need to do is different
(ie, see the `recover' command).

0. first, read fs(8).

1. check the file system, to get some idea of how much might
     have been damaged.  do a `check free' at a minimum.

2. type `users default' which will give the file server a default set
    of users that might at least allow you to connect to have a look round
   and perhaps save anything you might have an urge to save now.

3. boot the file server and hit a key within five seconds (as it says)
    to enter config mode.  type the command `allow', then `end' to start
    service.  the system will be in a mode that will allow you to do
    anything you need to do to mend things, including suppling new
    copies of /adm and /adm/* (check ownership and permissions before
    you next reboot the file server, otherwise you'll need to boot in allow mode again to set them), or reloading
    things from the CDROM following the usual installation instructions.
    all permission checks are suppressed in `allow' mode.

4. reboot the file server to cancel `allow' mode.