This is for SLES8 only, everything changes in SLES9.

grep dasdbl /proc/dasd/devices       # - to find major/minor numbers of device
mknod /dev/dasdbl b 94 
mknod /dev/dasdbl1 b 94 253          # - minor number + 1
dasdfmt -y -f /dev/dasdbl -b 4096 -p
fdasd -a /dev/dasdbl
pvcreate /dev/dasdbl1
vgextend vg00 /dev/dasdbl1