Multiplicity of dmesg in 4.8

[Malcolm Kay]

To day I install FreeBSD release 4.8 on a machine form the first time.

This is on a new machine so it could easily have as yet undetected
hardware faults.

I observe the 'dmesg' gives start up information not only for the latest 
boot but also information generated in a number of previous boots.

I've not seen this with earlier FreeBSD realeases including 4.7.

Is it normal for FreeBSD 4.8 or should I be looking for hardware problems?

I notice some change in that the files /var/log/dmesg.{today,yesterday} do
not seem to be produced.

Any help welcome,

Malcolm Kay