Why HP LTO Tape Drives Can't Fill a Tape

[Asuka17377]

I have a used LTO6 HP tape drive (made in 2013) from a friend's company and it's a barely used spare.
I bought a second-hand Dell H200E HBA card and 8088 cables from a local dealer.
Using the LTFS file system, the software uses fastcopy or Windows File Explorer to copy data.
But the strange thing is that it seems that LTO5 tape, whether it is IBM, Quantum, FUJI or Oracle, it seems that some of the last space, about 10GB or so, cannot be written...Writing the last 10GB space will cause the tape to become "problematic" , with an exclamation point next to the icon.
Does anyone know why?

 

[DavidWJohnston]

I run LTO5 - When using LTFS, there is an index partition and a data partition. I thought the index partition was 30GB but maybe it's adjustable. I'm not sure if that has anything to do with your observation or not.

I remember seeing a checkbox to allow storing actual files in the index partition. Maybe if you're super close to fitting your data on a single tape you could try that.

 

[Asuka17377]

I run LTO5 - When using LTFS, there is an index partition and a data partition. I thought the index partition was 30GB but maybe it's adjustable. I'm not sure if that has anything to do with your observation or not.

I remember seeing a checkbox to allow storing actual files in the index partition. Maybe if you're super close to fitting your data on a single tape you could try that.

I'm actually not very rich and I use LTO5 tapes most of the time too.
What I mean is: you get an LTO5 tape and it says 1.5TB capacity, I have 1.3TB on my computer after formatting, no problem.
What I want to ask is that when 1.28~1.29TB is written, there is about 10GB of space left on the tape. Any more writes corrupted the tape - it seemed unreadable and I had to roll back using the HPE LTFS tools.（My files are all videos, usually several gigabytes or more）
I mean, is the last 10GB or so of space really unusable?