The high interrupt load vanished after removing the CD-ROM drives from
both V210, as suggested by Mark Kettenis.
Now the CPU load is down to 0%, as one expects, and the systems are
much more performant and responsive than before :-)
# iostat -w 1
tty cd0 sd0 cpu
tin tout KB/t t/s MB/s KB/t t/s MB/s us ni sy in id
0 21 0.00 0 0.00 8.18 2 0.01 3 0 0 36 61
0 172 0.00 0 0.00 0.00 0 0.00 0 0 0 0100
0 57 0.00 0 0.00 0.00 0 0.00 0 0 0 0100
0 57 0.00 0 0.00 0.00 0 0.00 0 0 0 0100
0 57 0.00 0 0.00 0.00 0 0.00 0 0 0 0100
0 57 0.00 0 0.00 0.00 0 0.00 0 0 0 0100
0 57 0.00 0 0.00 16.00 2 0.03 0 0 0 0100
0 57 0.00 0 0.00 0.00 0 0.00 0 0 0 0100
^C
#
Thanks to Mark for his suggestion,
Rolf
