What does the following mean (output from systat):

Discs  wd4  wd5  cd0  wd0  wd1  fd0  md0 raid          64 fmin
seeks                                                  85 ftarg
xfers                 138  137            128             itarg
Kbyte                1256 1249           1256         523 wired
%busy                 3.2  2.4           94.4             pdfre

Why is raid 94.4% busy when the components (wd0, wd1) are only 3%
busy?  CPU is about 90% idle.

My raid0.conf looks like this:

START array
# numRow numCol numSpare
1 2 0

START disks
/dev/wd0f
/dev/wd1f

START layout
# sectPerSU SUsPerParityUnit SUsPerReconUnit RAID_level_1
128 1 1 1

START queue
fifo 100
#scan 400

Someone said I should be using "scan" instead of "fifo" with IDE disks.
Why is that?  Can I change this parameter without initializing the raid
set (ie. losing all my data)?

Thanks,

  -jm