disk usage
Looking at disk usage on any of these must be done using a tool built for it if you want an accurate measurement. General purpose tools like du will be inaccurate as they do not count things like duplicate copies in snapshots.
❯ sudo btrfs fi usage -T / [sudo] password for waylon: Overall: Device size: 465.26GiB Device allocated: 251.06GiB Device unallocated: 214.20GiB Device missing: 0.00B Device slack: 0.00B Used: 234.44GiB Free (estimated): 227.37GiB (min: 120.27GiB) Free (statfs, df): 227.37GiB Data ratio: 1.00 Metadata ratio: 2.00 Global reserve: 478.88MiB (used: 0.00B) Multiple profiles: no Data Metadata System Id Path single DUP DUP Unallocated Total Slack -- -------------- --------- -------- -------- ----------- --------- ----- 1 /dev/nvme1n1p2 239.00GiB 12.00GiB 64.00MiB 214.20GiB 465.26GiB - -- -------------- --------- -------- -------- ----------- --------- ----- Total 239.00GiB 6.00GiB 32.00MiB 214.20GiB 465.26GiB 0.00B Used 225.82GiB 4.31GiB 64.00KiB
-T for tabular format
mounting the drive
sudo mkdir /mnt/nvme1n1p2/ sudo mount -o subvol=/ /dev/nvme1n1p2 /mnt/nvme1n1p2
mounting a snapshot
snapper
btdu
sudo btdu /mnt/nvme1n1p2
btdu v0.5.0 @ /mnt/nvme1n1p2 --- / ----------------------------------------------------------------------------------- ~5.974 GiB [ ] /<DUP> ~239.1 GiB [##########] /<SINGLE> --- Details: ---------------------------------------------------------------------------- - Full path: /mnt/nvme1n1p2/ - Average query duration: 0.0002558 seconds - Represented size: ~245.0 GiB (607659 samples), ±0.0 B - Logical offsets: ..., 2659587804610, 2608834997278, 2688762158568 --- Explanation: Welcome to btdu. You are in the hierarchy root; results will be arranged according to their block group and profile, and then by path. Use the arrow keys to navigate, press ? for help. Samples: 607659 Resolution: ~422.8 KiB