It’s almost certainly tape, a single LTO9 cartridge can hold 18TBs of data for cheap compared to the equivalent drive.
Blu-ray is unlikely, only quad layer BR have a decent capacity at 125GB each and quality ones are hard to find these days. Sony has even stopped making their blu ray based Optical Disk Archival system thing.
It’s almost certainly tape, a single LTO9 cartridge can hold 18TBs of data for cheap compared to the equivalent drive.
Blu-ray is unlikely, only quad layer BR have a decent capacity at 125GB each and quality ones are hard to find these days. Sony has even stopped making their blu ray based Optical Disk Archival system thing.
It’s almost certainly spare space from massive S3 disk pools that’s unused.