Re: Tape for Longterm Storage
Are you sure about "you can generally interface a disk drive to a machine for a long long time"? Have you tried to connect a SCSI disk (anything earlier than UltraSCSI, but try a SCSI-1 SE disk for a real challenge) to a modern server? And older interfaces like ESDI, ST506, MASBUS or ESMD are long dead.
Even more modern technologies like IBM SSA are now dead. IDE and EIDE interfaces no longer appear on modern motherboards. Even when older HBAs are still available, they will be PCI adapters, and these are being eliminated in newer systems.
I believe that the SAS technologies are expected to be N+2 compatible, i.e. a first generation SAS disk will work with a SAS 3 adapter, but there is no guarantee that they will work with later adapters. Given the speed of evolution of such things, I expect disks to remain portable to current machines for 5 or so years after manufacture, and after that, you will have to rely on legacy hardware to be able to read them. Does not encourage me to use disk as a long-term archive medium.
This is partly by design, as the disk and system manufacturers want to continue selling systems, and they have built-in obsolescence.
My personal thought is that you would have more success reading a 2400' 1/2" NRZI mag. tape at 800bpi recorded using ar or tar from 30 years ago that you would an early SCSI disk, especially if it came from a Netware, VAX, PrimeOS or other proprietary OS.