One volume (RAID 5) on two enclosures?
I have two thunderbolt enclosures - one with 5 drives and one with 2 drives, all of them as JBOD. Is it possible to create one single RAID 5 volume of all seven drives?
Yes if you want. You can use up to 16 drives in a single volume.
No it does not, as long as the overall system is reliable.