What type of configuration do you have?
From one page I did find, it doesn't seem to be supported (although this isn't a SUN site)
Software RAID
The MD driver in the Linux kernel is an example of a RAID solution that is completely hardware independent.
The Linux MD driver supports currently RAID levels 0/1/4/5 + linear mode.
Under Solaris you have the Solstice DiskSuite and Veritas Volume Manager which offer RAID-0/1 and 5.
found here
SUN docs has this - which seems to support the other statement:
Concatenation maps data in a linear manner onto one or more subdisks in a plex. If you were to access all the data in a concatenated plex sequentially, you would first access the data in the first subdisk from beginning to end, then access the data in the second subdisk from beginning to end, and so forth until the end of the last subdisk.
The subdisks in a concatenated plex do not necessarily have to be physically contiguous and can belong to more than one VM disk. Concatenation using subdisks that reside on more than one VM disk is also called spanning.
Found at this
link