[rescue] Converting a SunOS 4.1.4 Disk from sun4c to sun4m

[Dave McGuire]

On 6/28/26 14:31, Todd Vernon via rescue wrote:
> Got my Sun 4.1.4 image to boot up on my SPARCstation 5 and QEMU 
> yesterday,  thought I would share the
> article, I see 4.1.4 stuff float around here from time to time.
> 
> https://oldsilicon.com/technologies/sunos-414-sun4c-to-sun4m-graft/ 

   An excellent write-up.

   At Digex in the 1990s, where we were maintaining a few thousand Sun 
machines, we maintained the "Digex standard load" of SunOS4.  It 
contained all of our local patches and configurations, got rid of NIS 
and other bad ideas, installed local builds of a few hundred packages, etc.

   It was an "all karch" load.  We replaced /usr/kvm with as symlink to 
/usr/kvm-sun4, /usr/kvm-sun4c, or /usr/kvm-sun4m.  OS copy scripts 
created and copied the filesystems, created that symlink as appropriate, 
took care of the bootstraps and the karch-specific kernel.  The 
filesystem copies were done with async writes turned on.  It all worked 
very well; we could have a new system up and running in about ten minutes.

   The standard load machines (sparc-proto.digex.net and 
m68k-proto.digex.net, would be called "golden" nowadays) were air-gapped 
and kept in cipherlock room.  We would occasionally physically connect 
them to the network to do rdist runs for installation of new software 
and md5 comparisons of files. (that was one of our local modifications 
to rdist, along with Kerberos integration)

   We did the same thing with 68K-based machines, with /usr/kvm-sun3 and 
/usr/kvm-sun3x.

             -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA