My original post suggested a problem with using an external monitor, but that proves to have been a red herring. Following secipolla's advice, I removed 'rhgb quiet' from the boot command and observed where the delay is occurring.
The problem appears to be with booting PostgreSQL, Apache and sendmail. I have recently started using Apache and PostgreSQL on this computer and have not rebooted since, so I fooled myself as to what was causing the boot delay.
The first slow-down is with "Started LSB: start and stop PostgreSQL server", which takes about 30 seconds to respond with OK. The second and longer pause in proceedings is with "Started LSB: start and stop Apache HTTP Server" which takes closer to a minute to respond. (These times are guesses - I have not run a stopwatch over them.) During these pauses, the system does not respond to Alt+Ctrl+F2 to display a terminal, so I am inclined to think this is a busy halt. The final issue, identified from boot.log, seems to be with "Starting sm-client: Starting LSB: start and stop sendmail", which responds quickly with "failed":
Once through these issues, the final steps and boot to graphical log-in dialog happens very quickly.
Started LSB: HSQLDB-Server.
OK <<<< Boot sequence runs ok to here.
Started LSB: start and stop PostgreSQL server.
OK <<<< Hangs for about 30 secs before OK
Started LSB: start and stop Apache HTTP Server.
OK <<<< Hangs about a minute before OK
Starting sm-client: Starting LSB: start and stop sendmail failed, see 'systemctl
status sendmail.service' for details. <<<< Fails quickly
For the sendmail failure, I executed the suggested sommand:
[doug@cardraeh ~]$ systemctl status sendmail.service
sendmail.service - LSB: start and stop sendmail
Loaded: loaded (/etc/rc.d/init.d/sendmail)
Active: failed since Sat, 23 Jun 2012 10:15:25 +1000; 23min ago
Process: 1426 ExecStop=/etc/rc.d/init.d/sendmail stop (code=exited, status=0/SUCCESS)
Process: 1446 ExecStart=/etc/rc.d/init.d/sendmail start (code=killed, signal=TERM)
Main PID: 1278 (code=exited, status=0/SUCCESS)
├ 1542 sendmail: accepting connections
└ 2564 sendmail: Queue runner@01:00:00 for /var/spool/clientmqueue
I'm not sure what this sendmail.service information is telling me. At first glance, it appears to say that sendmail has not started properly, but Evolution seems quite happy to look at my local mail queue, which I would not have expected it to do if sendmail was down.
So, the questions now boil down to "how do I speed up booting PostgreSQL and Apache?" and "what is going on with sendmail?".