Does that unit have a PCIe slot? If so, get an external HBA, a disk shelf and cable between them, then populate said disk shelf with large capacity HDD’s and you’re off data hoarding 
Disk shelf: https://www.aliexpress.com/item/1005005901398655.html
Cable: https://www.aliexpress.com/item/1005006615445631.html
External HBA: https://www.aliexpress.com/item/1005004457790634.html
WD Ultrastar 16TB HDD: WD Ultrastar DC HC550 16TB SATA 3.5" Enterprise HDD WUH721816ALE6L4 0F38466 232 | eBay
HTH!