hi, the diferences between i/o physical (hard disk) and logical names are:
try this commands
#sysdef
or
#prtconf | grep -v not
example:
# prtconf | grep -v not
System Configuration: Sun Microsystems sun4d
Memory size: 256 Megabytes
System Peripherals (Software Nodes):
SUNW,SPARCcenter-2000
options, instance #0
cpu-unit, instance #0
TI,TMS390Z55, instance #0
bootbus, instance #0
zs, instance #0
zs, instance #1
cpu-unit, instance #1
TI,TMS390Z55, instance #1
mem-unit, instance #2
io-unit, instance #3
sbi, instance #0
cgsix, instance #0
SUNW,hme, instance #0
dma, instance #0
esp, instance #0
sd, instance #0
sd, instance #1
sd, instance #2
sd, instance #6
QLGC,isp, instance #0
sd, instance #8
sd, instance #9
pseudo, instance #0
good luck