Mac OS X forum: os x processes disk activity: virtual memory ?

It may well be that the continuous disk activity I experience with my Mac Pro dual 2.26 GHz Quad-Core Intel Xeon (yes we came a long way since the Macintosh SE...) is nothing to worry about. But I do not understand why so much activity is going on even when only the Finder, Safari and Activity Monitor is running. In the Activity Monitor window I notice a process named "VCStatus" that is very active (apparently continuously starting, stopping, receiving a new PID every time) and that the process called "notifyd" has accumulated a virtual memory size of 2,37 GB. Activity Monitor shows that the rate data is read and written have an average of about 2 MB/sec (data written far dominates).

Because I really like a quieter Mac my question is for the Mac OS X experts among you:
- is this disk activity usual ?
- what is the function of these processes (VCStatus,notifyd) ?
- where can I read and learn about hidden OS X processes like this ?
- can I tell OSX to use RAM in stead of Virtual Memory ?

I cannot include screen clippings in this post, but they are available for those interested.

thanks.