LTO-8 media soon after its launch was in shortage, due to a patent legal dispute between FujiFilm and Sony the 2 largest manufacturers of LTO media. LTO-8 tape drives were shipped but the media itself wasn't available. The customer could use LTO-7 media in their LTO-8 drive, but that's not what they bought an LTO-8 tape drive for.
A temporary solution came in the form of LTO-7 type M ( which was initially called LTO-8 type M). It was essentially an LTO-7 media that can be formatted to a 50% higher capacity in LTO-8 tape drive. All of a sudden it became a great value preposition. Invest in an LTO-8 tape drive now and utilize any LTO-7 tapes you have with 50% more capacity - your LTO7 drive can't do it so upgrade now.
The Solution of using LTO-7 as LTO-7 type M in LTO-8 drive, today also is a very cost effective way, in fact LTO-7 Type M ( or M8) media has one of the lowest cost per TB among all LTO tapes.
If you own an LTO-8 tape drive, then you can use an LTO-7 media as M8, what you need is
- You need Previously unused LTO-7 media. If you have used the LTO-7 media previously, you can't reformat it as M8 media.
- You need M8 barcode labels. Without these labels your library or autoloader won't recognize M8 media and will format LTO-7 as 6TB.
- You need a tape library or autoloader. If you have a single drive, you will have to obtain a preformatted LTO M8 Media since your standalone drive can't read a barcode.
Till the prices of LTO-8 media come down ( historically the launch price of LTO-8 is the highest ever among launch prices of all other tapes, and its holding steady too), M8 media offers you a higher capacity at the lowest cost per TB - that's exactly what you know your tapes for. It makes a lot of sense to format and use LTO-7 media as M8 for use in your LTO-8 drive.