So I have a building stack of old ATA and now some smaller SATA hard drives. Can I make a BIG RAID volume with multiple different drives? Yes they start @ 20mb but some are retires are as big as 4-500mb. Any Ideas?
IF you have the data ports on a RAID-capable controller and the power supply connectors available (always easy to add more via adapters) you can go two ways. Either simply install and use them a separate drives or use the JBOD version of RAID to combine several into one volume treated as a single drive. I'd be inclined not to use the smallest ones.
Have you considered mounting a few in one or more external drive enclosures and using them as backup devices that can be disconnected and stored offsite?