I set the metronome with a count in of 2.   I hit the recording button, and the midi track counts in to record.  While the count in is happening, I play the drum riff to warm up.  When the recording is over, there is a pile up of midi notes at the very beginning of the track.  When I play the track, they all play at once, and it is very loud.  They notes must all be erased to use the track.  Can these warm up notes simply be made unrecordable, for the count in period?
thanks,
wadrum

This behavior goes back to Cakewalk for DOS. The intent is to avoid missing a note that's played a couple milliseconds before the transport starts moving. SONAR assumes all early events were intended to be played at 1:00:000. There's no way to disable it.

Maybe record punch-in could be used for this purpose.  Try setting a punch-in configured where you want your first recorded measure and start recording a measure or two early.

I usually don't start recording until the 4th measure of thereabouts. So that would give you a few warm up measures without a pile-up.
If you want to later print the score, split and delete the first measures and slide everything over to 1.