You have an unmounted btrfs file system: # btrfs filesystem show Label: 'Btrfs' uuid: 7bfe3239-47ee-442b-b9f8-49f88b6b1be4 Total devices 3 FS bytes used 300.51MB devid 2 size 4.88GB used 1.06GB path…

You have an unmounted btrfs file system: # btrfs filesystem show Label: 'Btrfs' uuid: 7bfe3239-47ee-442b-b9f8-49f88b6b1be4 Total devices 3 FS bytes used 300.51MB devid 2 size 4.88GB used 1.06GB path /dev/sdd devid 1 size 4.88GB used 580.00GB path /dev/sdc devid 3 size 4.88GB used 1.50GB path /dev/sdb You have these mounted devices: # df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_exam1-LogVol_system 9.6G 3.3G 3.9G 46% / tmpfs 499M 0 499M 0% /dev/shm /dev/sda1 485M 77M 384M 17% /boot You have a mount point for the btrfs file system: # ls -all /btrfs total 0 drwxr-xr-x. 1 root root 0 Aug 12 10:17 . dr-xr-xr-x. 1 root root 276 Aug 12 10:36 .. Examine these steps: 1. Manual defragment is not needed. Btrfs will defragment it automatically. 2. btrfs device defragment /dev/sdd 3. btrfs filesystem defragment /btrfs 4. btrfs device delete /dev/sdb /btrfs 5. mount UUID=7bfe3239-47ee-442b-b9f8-49f88b6b1be4 /btrfs 6. btrfs device delete /dev/sdb /dev/sdd What is the correct order to delete the /dev/sdb device from the btrfs file system and for defragmenting the reduced file system?