Migrating from hardware to software RAID

I have an old PCI-X controller running 8 drives in RAID 5. I'd like to dump the controller and go to software RAID under Ubuntu. Is there a way to do this and retain the data from current array? **EDIT:** (and a slight tangent) The answers below are certainly fine, but here's a bit of added detail in my specific situation. The hardware raid was being done by an old Promise raid card (don't remember the model number). My whole system went down (dead mobo, most likely) and the old controller was a PCI-X card (not to be confused with PCI-e). I asked the question hoping to salvage my data. What I did was buy another Promise (HighPoint) card, and plug all the drives in and install Ubuntu. I was expecting to have to rebuild the array, but surprisingly enough, the HighPoint card saw the old array and brought it up clean. Moral of the story - it looks like at least Promise controllers store their metadata on the arrays themselves, and appear to have some amount of forward compatibility.