When executing a capacity migration or consolidation on a highly utilized Pure Storage FlashArray (such as an //X90 Gen 2 at 90% capacity), physical and logical space limitations dictate the required procedure. The FlashArray chassis only contains 24 front-facing capacity drive bays. In this scenario, the chassis is fully populated with 10 drives in slots 0-9 and 14 drives in slots 10-23.

Because all physical chassis slots are occupied, there is nowhere to physically insert the new 91TB (10 x 9.1TB) DirectFlash Modules. Furthermore, because the array is at 90% capacity, there is insufficient logical free space remaining to evacuate the 22TB data pack into the existing 63TB pack's free capacity. Standard evacuation requires the system to non-disruptively move data off the target drives before they can be safely removed, which is mathematically impossible here without external capacity.

To resolve this, the officially supported method is to install a temporary "swing shelf" (Option B). A swing shelf acts as a temporary expansion vessel. The Implementation Engineer physically racks the swing shelf, connects it to the array, and inserts the new 91TB data pack into it. Purity can then safely evacuate the data from the old 22TB chassis data pack onto the new drives in the swing shelf. Once the evacuation completes, the old drives are decommissioned and removed, the new 91TB drives are seamlessly relocated into the chassis slots 0-9, and the swing shelf is removed and returned.