Retried amtatpetype with another new tape yesterday.
No success. Labelled and tested with 64k blocksize, still about 200 GB size only. Could the older kernel somehow play a role here? The output of amtapetype says: "LEOM is not supported for this drive and kernel" I try to set "LEOM false" now explicitly. Linux version 3.12.13-gentoo ... yeah, I know ... But the server is ~3 hrs away and old, reinstallation without guarantees is somehow inefficient. (No IRMC/ILO remote console for doing kernel change easily) - It looks like a LTO2 tape ... although the customer told me it says LTO3 on the cartridge (and has a correct product number). mt status detects it as density=0x44 as well, but the capacity and speed looks like LTO2. Strange.