SUMMARY: Ultra-5 Rebooting

From: G. Dimitoglou (
Date: Wed Jan 13 1999 - 12:43:08 CST

Dear SUN-ers,
Thanks to all for your responses. The answer was with a faulty
motherboard. As soon as it was replaced, the system became stable.

Following pls find my original posting/question and answers.

> Fellow SUN Mgrs,
> We have an Ultra 5 running Solaris 2.6 with all required patches
> applied that reboots every night.
> No indication of the problem in the /var/adm/messages files and I have
> also changed /etc/init.d/sysetup trying to trap whatever is causing it
> but with no luck.
> The system was fine until we had a hard disk crash a month ago and Sun
> Service came out to change it. The new drive would not accept the OS,
> we tried a second drive, then we changed the CD-ROM drive and cabling
> thinking that it was a CD-ROM drive problem that was causing the OS failure,
> we changed almost all cabling and after yet another hard drive the OS was
> succesfully installed.
> We think that this may be a motherboard problem and we have a call in
> for a motherboard change but we are getting desperate. After a new mb
> the system will be virtually new inside...
> Any thoughts, anyone has any similar experiences?
> Thanks
> George
From: Eric Lewandowski <>

We havent had this problem w/ Ultra-5, but we have had a very very similar
problem w/ our Ultra-1's... the probelm turned out to be that the fan was broke
and the processor was heating up too much and rebooted from that. Hope that

From: "Auteria Wally Winzer Jr." <wally.winzer@ChampUSA.COM>

It definitely sounds like a motherboard problem.
Get it changed ASAP. You should be ok from that point on.

From: Jim Ennis <>

Did you check to see if the system is doing the power save shutdown that
comes with 2.6 installs.

From: Tom Erickson <>

Did you check root's crontab? Maybe there is an
entry for a reboot in there. Also, anyone else
have enough privileges to have same in their

Good luck - Tom Erickson



I had a similar experience with an old SparcServer 2, that used to reboot
every morning at around 7:00am with no warning. We painstakingly piece by
piece completely swapped out the machine, and the problem still occurred,
and wasn't occuring for another Sparc 2 in the same scope cabinet. We even
had a DRANETZ power monitor to see if the problem was power related (eg
local factories starting up causing power spikes etc). No joy.

In the end, it turned out to be rebooting when the office lights were
turned on - a large number of fluourescant lights. I *think* that the
problem was something to do with the high electromagnetic fields that are
induced by the fluourescent bulbs starting. The machine at the top of the
cabinet was saved by the thick, shielding steel lid. But we never proved
that ;-)

One urban myth...

From: Timothy Lorenc <>

Did you try swapping the memory with other memory?

-Tim Lorenc

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