Baobab (Disk Usage Analyzer) not fully showing usage?

[NobinPegasus]

Here's the output of Baobab. It shows that I have 750 GB total. But when I press on it I could only find 566.7 GB. Where is the rest of the 124 GB? Why is it not showing?

pegasus@pegasus:~$ df -h
Filesystem      Size  Used Avail Use% Mounted on
tmpfs           1.6G  3.9M  1.5G   1% /run
/dev/nvme1n1p3  699G  528G  136G  80% /
tmpfs           7.6G     0  7.6G   0% /dev/shm
tmpfs           5.0M   16K  5.0M   1% /run/lock
tmpfs           7.6G     0  7.6G   0% /run/qemu
/dev/nvme0n1p1  256M   38M  219M  15% /boot/efi
tmpfs           1.6G  156K  1.6G   1% /run/user/1000

 

[osprey]

It's complicated. See: https://unix.stackexchange.com/ques...-so-many-different-ways-to-measure-disk-usage
Different apps and commands read in their own ways.