After almost a decade of using unRAID to keep my most important production files in one place, I have found that copying/moving parts or all of the content of one drive to another can take anywhere from a few hours to a few days, depending on its content. The slowest are my drives that contain whole computer backups (in .img or .sparsebundle formats) or those of my email accounts (with 100K+ messages). While I know that compressing a 1.5TB .sparsebundle might also take a significant amount of