how good is the data reliability with CD ROM and DVD RAM?

[Fred Cisin]

On Sat, 21 Jul 2018, Carlo Pisani via cctalk wrote:
> what about MO? (magneto-optic disks)
> - WORM (write once, read many)
> - WMRM (write many, read many)
> and what about magnetic-tapes? (e.g. DDS4, DLT, LTO2)
> which of them lasts for the most?
> MO units and disks are a bit costly
> say >=50 euro for 4.5Gbyte R/W cartridge
> and say >=500 euro for the driver unit (SCSI)

"M-Disc" has the longest longevity claims.

'course they're all extrapolation.  In a thousand years, it will be 
obvious that they are exaggerated.