I tried to get both Linear and Raid 0 running on a Sun SparcStation LX with 24 Megabytes of memory and three SCSI hard drives. I tested each drive separately and they all worked fine. When I tried to do a mkraid /dev/md0 (after loading the linear and raid0 modules and setting up the examples listed in the docs) the machine started doing very strange things (like VI couldn't find a symbol in the libc shared library). The mkraid command returned an "invalid argument /dev/md0" error message and a lot of kernel raid debugging messages printed out from the kernel. I then grabbed the latest version of raidtools-19990421-0.90 from the listed site and was able to get raid0 working but not linear mode. (Please see my other bug report on the initscripts package having to do with loading modules before the raidstart command is run). Please let me know if I can do any other specific tests that would help with the problem.
I was not even able to mkraid on my sun4m. It sends a kernel messages 'Unimplemented SPARC system call 140'. After looking through the latest source, I defined __usparc__ in raid_io.c, recompiled, and was able to mkraid. Then strange things happened such as not being able to execute /bin/vi (cannot execute binary file).
Closing ancient bug, please reopen if still relevant on !sparc in current release (7.1).