SunOS 5.6 vs 5.8 HardDisk

Hi all,
I am not sure I am in the correct forum or not, but I would appreciate if somebody from here can help me out.
My processing equipment currently is using Unltra5 SunOs 5.6 with 8.6 GB hard disk, newer UltraSPARC SunOS 5.8 is with higher hard disk capacity. I am wondering how much hard disk capacity SunOS 5.6 and 5.8 can support? next question is, can I install slave hard disk to my old Ultra5 SunOS 5.6 worksation?
If I would to install a RAID 0 on my Ultra5, will it help? pls help

if you have system handbook which can be download in SUN site, you can find your system in the end of life systems, and you can see suitable disks for system by means of part number of your disk. This will be healty information for you absolutely.

Sincerely
Ali

Thanks for the help.

I hope my questions not trobled you all as I am not from this UNIX feild.

I am wondering also should I install a "Slave" hard disk to my SunOS5.6 CPU? how should I transfer the data?