Re: Uptime: The Movie

[TYSON@ai.sri.com (Mabry Tyson)]

This last weekend we just had a planned electrical system changeover that might
have caused power spikes so we only left up our mail servers.  Before that
though, I did a :SHOW USERS and one host that is no longer in use had been
idle 3146 hours (= 18.7 weeks).  I don't know when it was booted though.

In February, 1989, I sent out a message to SLUG reporting we had one
host that was up >6 months, another >5 months, and some more >2 months.
The host that was up >6 months was used daily as the workstation for a
person doing image processing (Image-calc) + ZMAIL + Latex.  I think it
was up something like 8 months before we booted it to put on new
software.   I typically see hosts up for months.

Our server currently has only been up 5 weeks but has done 212M conses
(according to :SHOW GC STATUS).  The measure of 500M conses that someone
mentioned can be put into perspective.  Of course on the machine that is
doing image processing, most of the work is done without doing consing.


To give some measure of comparison to other platforms, we ran 7 Sun
Sparcstation 2's over one weekend (11-20 hours each) in parallel doing
different parts of a large task.  Each portion took 10-20 billions of
ephemeral conses (Sun Common Lisp (aka Lucid)).  Of those 7, two
machines died with hardware problems.  Just before the weekend, I
removed some memory from one of the machines because it had generated
parity errors the weekend before.  (The machines had between 32 and 64
MB of memory.)  We have discovered that the day-to-day operations on our
Suns (including multi-hour Prolog runs) do not exercise the machines as
much as Lisp does.


Of course, what do you expect?  Our hardware is from the "good old days"
when machines were well built :-).   How many people do you know whose
(non-Symbolics) computers are older than their children or cars?