Re: Core dumps & restarting

Doug Ledford (dledford@dialnet.net)
Wed, 06 Nov 1996 22:18:21 -0000 ()

On 05-Nov-96 alan@lxorguk.ukuu.org.uk wrote:
>> Sounds like what you *really* want is the thing Novell calls SFTIII. I've
>> never seen it myself, but I gather the idea is to have (usually) two
>> machines with identical hardware (and preferrably a *very fast* dedicated
>> network connecting them), acting to the outside world like a single
>> machine. One of them dies, you clients never notice.
>
>Its impressive. I saw a demo of this at a network show and they were picking
>random failures and doing them to servers. Sort of spin the dial - power fai
l
>so off one went and one it came again. They apparently ended the show by
>flattening a compaq server with an anvil while the other continued - alas
>I missed that bit.

We built one of those once (not too much demand for that type of server setup
in our little town of 150,000 rednecks). Used a FDDI backbone between the tw
o
servers, and Cogent 4 port ethernet cards for client access. Kind of nice
having two servers where you configure one of them all the way, configure the
other just to the point of SFTIII, then let the partially configured server
update its own configuration to match the finished server. Ditto for anythin
g
else you might do while one server is down. Even went so far on the matching
kernel stuff that if you pull up the monitor screen, it comes up on both
servers and the keystrokes are mirrored to both servers (this little feature
might not be so great if you find a sequence of keystrokes that will crash a
server, since it could take both servers down simultaneously, depends on
whether the keystroke gets mirrored before the crash occurs :)

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