[comp.sys.sgi] Booting backup kernel

ackerman@uvm-gen.uvm.edu (Steve Ackerman) (08/13/89)

	Tonight, I accidently clobbered my Personal IRIS kernel.
Fortunately, I had a backup of it in /unix.old.  Unfortunately, I
couldn't figure out how to tell the PROM Monitor to boot from
/unix.old instead of /unix.  Is it possible to do this?  If someone
could tell me where in TFM I could find DETAILED information on the
monitor, I'd appreciate it.

thanks!

--
============================================================================
Steven Ackerman, 			 |  EMBA-CF University of Vermont    
uunet!uvm-gen!ackerman                   |  Burlington, Vermont 05401 
Internet: ackerman@uvm-gen.uvm.edu       |  Telephone: (802) 656-2926

elkins@topaz.rutgers.edu (George Elkins) (08/14/89)

In article <1263@uvm-gen.UUCP>, ackerman@uvm-gen.uvm.edu (Steve Ackerman) writes:
> 	Tonight, I accidently clobbered my Personal IRIS kernel.
> Fortunately, I had a backup of it in /unix.old.

You could use the boot command from either the PROM monitor level,
or from sash (stand-alone shell).  The boot command attempts to
boot sash, in both cases.  So when in sash, you must use the -f
option.  At the PROM monitor level you could type
	boot dkip(0,0,0)unix.old
or from sash you could type
	boot -f dkip(0,0,0)unix.old

The general format for the boot command from sash is:
	boot [-f device(address)file] [arguments]

You may need to modify the above for your particular device,
address and desired init level, etc.  E.g. from PROM,
	boot dksc(0,1,0)unix.old initstate=1
for scsi disk controller, putting machine into single-user mode.

(All of this is from memory, so it could be slightly wrong.  Also,
my experience is with Iris 4D.)

George Elkins

mitch@rock.sgi.com (Thomas P. Mitchell) (08/17/89)

In article <Aug.14.00.09.48.1989.8000@topaz.rutgers.edu> elkins@topaz.rutgers.edu (George Elkins) writes:
>In article <1263@uvm-gen.UUCP>, ackerman@uvm-gen.uvm.edu (Steve Ackerman) writes:
>> Fortunately, I had a backup of it in /unix.old.
Good man.
>option.  At the PROM monitor level you could type
>	boot dkip(0,0,0)unix.old
>or from sash you could type
>	boot -f dkip(0,0,0)unix.old
>
>The general format for the boot command from sash is:
>	boot [-f device(address)file] [arguments]
>
>You may need to modify the above for your particular device,
>address and desired init level, etc.  E.g. from PROM,
>	boot dksc(0,1,0)unix.old initstate=1

CAUTION HERE:  initstate should be checked very carefully
		s =/= S
		s =/= 1
		S =/= 1
		1 =/= 2 
		1 =/= 3   etc.
         and the transitions from one to another are not 
         always symmetrical (cannot in some cases). 

#define =/= not necessarily the same.


 
Thomas P. Mitchell (ARPA:mitch@csd.sgi.com, UUCP:  {decwrl,ucbvax}!sgi!mitch )
Rainbows -- The best (well second best) reason for windows.