On Wed, Dec 15, 2021 at 10:31:13PM +0800, Jingyun He wrote:

Hello,
I have a 14TB WDC HM-SMR disk formatted with BTRFS,
It looks like I'm unable to fill the disk full.
E.g. btrfs fi usage /disk1/
Free (estimated): 128.95GiB (min: 128.95GiB)

It still has 100+GB available
But I'm unable to put more files.

We'd need more information to diagnose that, eg. output of 'btrfs fi df'
to see if eg. the metadata space is not exhausted or if the remaining
128G account for the unusable space in the zones (this is also in the
'fi df' output).

Do you know if there are any mkfs/mount options that I can use to
reach maximum capacity? like mkfs.ext4 -m 0 -O ^has_journal -T
largefile4

There are no such options and the space should be used at the full range
with respect to the chunk allocations.