[Sunhelp] [Help] ring buffer overflow message

[Doug McLaren]

On Fri, Jun 25, 1999 at 11:14:25AM +0100, Robert.Cross at scottish-newcastle.co.uk wrote:

| I keep getting the following message appearing on the syslog destinations:
|  NOTICE: zs1:ring buffer overflow
| 
| I've recently had to add dial-in modem access, so I'm presuming that this 
| message originates somewhere in the SAF/SAC subsystem.

That sound right ...
 
| Is there anyway to stop the situation that causes the message happening, e.g.
| extend the buffer.

Not sure about being able to fix it (without buying some expensive
serial port card, of course) , but from the Solaris FAQ at
http://www.wins.uva.nl/pub/solaris/solaris2.html -

   3.28) I'm having troubles with high-speed input on the Sparc serial
   ports. What should I do?

   Try using UUCP. The Solaris 2.x sparc serial driver has trouble
   receiving data at or above 9600 bps. Symptoms include sluggish
   response, `NOTICE: zs0: silo overflow' console messages, sending
   spurious control-Gs to the serial port, and applications that cannot
   be killed even with `kill -9'. This problem surfaces in many
   applications, including Kermit and tip. UUCP seems immune, though,
   because its protocol throttles input sufficiently.

   People have reported success in later releases of Solaris (2.3+). 

   Solaris 2.5 supports much higher baudrates and hardware flowcontrol in
   two directions. The latter is also available as a patch for 2.3
   (102028) and 2.4 (102845, note that this patch conflicts with patch
   102062-08, which should be installed first if at all). The zs device
   can be set to 38400bps in 2.4 and earlier and 76800 in 2.5 and later.

   The latest UltraSPARC systems with PCI have a newer serial chip, with
   the "se" device driver. It can sustain speeds of upto 400k bps.

This looks really out of date, but I doubt anything has really changed
(except for the exact error message.)  Ultimately, the problem is that
older Suns (non Ultra) have pretty crappy serial ports.

-- 
Doug McLaren, dougmc at frenzy.com