~ # mkfs.btrfs /dev/sr0
btrfs-progs v6.3.3
See https://btrfs.readthedocs.io for more information.
ERROR: '/dev/sr0' is too small to make a usable filesystem
ERROR: minimum size for each btrfs device is 114294784
~ # df -h /dev/sr0
Filesystem Size Used Avail Use% Mounted on
udev 10M 0 10M 0% /dev
Gentoo Wiki 说也许我必须这样做，所以我就这么做了。 （措辞非常不清楚）。但没有效果。
~ # dvd+rw-format /dev/sr0
* BD/DVD�RW/-RAM format utility by <[email protected]>, version 7.1.
* 25.0GB BD media detected.
* formatting 75.0/
这可行，但生成的文件系统大小只有 7.7 MB。
~ # mkfs.ext4 /dev/sr0
mke2fs 1.47.0 (5-Feb-2023)
Creating filesystem with 5270 2k blocks and 2640 inodes
Allocating group tables: done
Writing inode tables: done
Creating journal (1024 blocks): done
Writing superblocks and filesystem accounting information: done
~ # mkdir /media/optical
~ # mount -t ext4 /dev/sr0 /media/optical
~ # df -h /media/optical
Filesystem Size Used Avail Use% Mounted on
/dev/sr0 7.7M 20K 6.9M 1% /media/optical