Re: svn - cannot allocate mem

[Alexander Schreiber <als%thangorodrim.ch@localhost>]

On Mon, Oct 02, 2023 at 10:24:20AM +0000, Riccardo Mottola wrote:
> Hi John,
> 
> John Klos wrote:
> > 
> > Do you have a machine near your SPARC that you can ssh / telnet to and
> > that can talk to the serial console of the SPARC?
> 
> 
> Yes, I have such a setup... eventually I configured it given the
> "oddball" systems I like to keep running. I have a small x86 system with
> RS232 (so I know its serial console is working reliably and I am not
> fighting against other ghosts) that now double-acts as a file server and
> serial console machine. I can connect then "once" to my SPARC and
> SPARC64 systems or Raspberry, MIPS boards.
> 
> I used laptops, but sometimes you really fight getting the correct
> serial console working, should be easy...but. Also they are getting scarce!
> 
> The only drawback is that with Netra and Fire, I can just plug-in and
> plug-out the serial cable.
> 
> On SS4/SS10/SS20 if I do plug out I usually hang the machine due
> debugger, I think it interprets a break or such. SO I need to run both
> systems and both connected to each other, a little inconvenient to do
> always.

Yes, that is the old Sun + serial console cable trap. Unplugging the
serial cable tends to be interpreted as IIRC "break" (same as Stop-A on
the keyboard) and hands execution off to the firmware console, which looks
as if the system just hangs. Plug the cable back in and type "continue"
and execution is handed back to the OS.

That's the reason why there are serial console servers marketed as
"SUN safe", because they won't generate a break signal when disconnecting
the serial console session.

IIRC there is a way to suppress this behaviour, but it has been ages
since I last looked into it.

Kind regards,
           Alex.
-- 
"Opportunity is missed by most people because it is dressed in overalls and
 looks like work."                                      -- Thomas A. Edison