I'm upgrading my Mac Pro (2008) to a 2012 tower. In my old machine I have 3 x 1TB drives software striped to make a 3TB volume. Is it possible to straight swap them slot for slot into the new machine or is there striping data needed on my old Mac?
If you don't get a solid answer, my take is that I would not try this, without a absolutely current backup of the data. It's been my experience that RAID arrays do not travel at all. I have attempted to move two RAID 1 disks and the RAID broke, and I was unable to restore the actual RAID (the data was safe).
I don't think that you can put the old drives in a new machine and have them then recognized as non software RAID array, then apply the old RAID like applying preferences. I would bet money that the old Array will be broken, and unuseable. Given that it's a stripe and not RAID1 you would be looking at possibly losing *all* your data. Why? Because when you first bring the three drives up, prior to the software RAID being formed, the drives will probably be setup as written into preferences as non RAID. (what you see when you do a "About this Mac" and System Report. ) I don't think there is anything to allow you to import a setting prior to this being written. Could there be a tool out there somewhere? Maybe. I'n not aware of one.
The advice to make a current backup before proceeding with any modification of an array is good. Apple software raid writes quite a healthy amount of metadata to each disk so it ought to be capable of assembling the array if all of the drives are moved to another OS X system. If it doesn't, I'd consider it a bug. But before doing it, I'd budget the time necessary to do a complete recreation of the RAID and a restore from backup - just in case it comes to that. If that down time can't be allocated then it's not a good time to do the migration.