I have a whole bunch of old towers I've accrued over the years, and family audio CD and DVD collections. Now hard drive space has become a premium for the backups, but I bought a whole bunch of powered SATA to USB adapters and a PCIe slot USB hub for my desktop. Had multiple CDs backing up at a time using every disk drive that still works. ExactRip, configure the drive, and then just swap out discs as needed while I worked from home.

Haven't moved on to DVDs yet. CDs are easy, you just use ExactRip to rip to FLAC. Haven't figured out a general use way for DVD ripping yet, especially because whether I want the special features backed up or not, or multiple audio streams, depends on the disc.