mckee@MITRE.ARPA.UUCP (04/01/87)
Based on some envelope calculations, described below, I estimate
that the peak number of simultaneous users is 10% of the potential
users. Is this estimate in accord with your experience?
The system I use here at MITRE is a VAX 8600 running Ultrix. I have
recently had occasion to be interested in the peak number of
simultaneous users as a percentage of the number of possible users.
So, on 24 March, I copied the /usr/users file and found 551 entries,
some of which had not logged-in since 1985! Recognizing that some user
accounts simply forward mail to another system, I deleted every entry
whose last login was 28 February, or earlier. That left 191 users that
had logged-in at least once during the period 1-24 March.
Over the past several months I have, at unplanned intervals, run the
Unix "who" command that lists all logged-in users. The usual response
is 10 to 15 users; very rarely does the number equal or exceed 20. The
estimate made above follows from this data.CERF@A.ISI.EDU.UUCP (04/02/87)
10% represents a high usage rate. MCI Mail had 16000 users/VAX but only a small % (0.5-1%) were ever trying to get on at once. Vint