为什么“要擦洗的总数”比“分配的设备”大很多。
29.1TiB与21.24TiB是一个巨大的差异。
设置：我有一个 btrfs RAID 阵列。由于转换不完全，它具有 RAID1 和 RAID5 的混合数据块。但正如我所读到的，这并没有什么坏处。
btrfs f u -T .
Overall:
Device size: 54.57TiB
Device allocated: 21.24TiB
Device unallocated: 33.33TiB
Device missing: 0.00B
Used: 20.52TiB
Free (estimated): 31.00TiB (min: 8.99TiB)
Data ratio: 1.10
Metadata ratio: 4.00
Global reserve: 512.00MiB (used: 64.00KiB)
btrfs scrub status .
UUID: yaya
Scrub started: Sun Apr 3 01:15:01 2022
Status: running
Duration: 55:56:56
Time left: 12:46:52
ETA: Tue Apr 5 21:58:54 2022
Total to scrub: 29.10TiB
Bytes scrubbed: 23.69TiB
Rate: 123.33MiB/s
Error summary: no errors found
btrfs fi df .
Data, RAID1: total=10.58TiB, used=10.21TiB
Data, RAID5: total=8.68TiB, used=8.58TiB
System, RAID1C4: total=32.00MiB, used=2.42MiB
Metadata, RAID1C4: total=23.00GiB, used=22.02GiB
GlobalReserve, single: total=512.00MiB, used=0.00B
Ubuntu 20.04 LTS
Versions: btrfs-progs v5.4.1
Kernel: 5.13.0-39-generic #44~20.04.1-Ubuntu SMP