WAL monitoring and optimizing

Hi, i'm running 7.2.3 (on RHL7.3). I've read the "WAL Configuration"
section of the manual:

http://www.postgresql.org/docs/view.php?version=7.2&idoc=0&file=wal-configuration.html

I've set wal_debug = 1 in postgresql.conf, but there's no example
of how LogInsert and LogFlush are logged. I can find many

DEBUG:  XLogFlush: request 6/6D8F54BC; write 6/6E13ECB8; flush 6/6E13ECB8

lines in my log, but no XLogInsert. There are lot of

DEBUG:  INSERT @ 6/70DC8744: prev 6/70DC8564; xprev 6/70DC8564; xid 372353616; bkpb 1: Btree - insert: node
9468978/12901623;

lines, but it's not clear if they are calls to LogInsert or something
different. They also come in different kinds (Btree - insert,
Heap - update, Transaction - commit, XLOG - checkpoint:, maybe others)
and I don't know which ones I should be looking for.

I've got 7365 'XLogFlush:' lines and 23275 'INSERT @' lines in the
last 9 hours. Should I increase the number of WAL buffers?

TIA,
.TM.
--
      ____/  ____/   /
     /      /       /            Marco Colombo
    ___/  ___  /   /              Technical Manager
   /          /   /             ESI s.r.l.
 _____/ _____/  _/               Colombo@ESI.it