1BTRFS-SPACE-CALCULATOR(1) Btrfs Space Calculator BTRFS-SPACE-CALCULATOR(1)
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6 btrfs-space-calculator - calculate usable and wasted space
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10 btrfs-space-calculator [args] sizes
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14 The btrfs-space-calculator program shows the amount of allocatable
15 space on btrfs physical and virtual level, and the amount of
16 unallocatable space resulting from having differently sized block
17 devices added to the filesystem.
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19 In a btrfs filesystem, raw storage is shared by data of different types
20 (System, MetaData and Data) and profiles (e.g. single, DUP, RAID1).
21 Also, a filesystem can have multiple block devices of different sizes
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24 An example:
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26 -$ btrfs-space-calculator -m raid1 -d raid1 2TB 500G 1TB
27 Target metadata profile: RAID1
28 Target data profile: RAID1
29 Mixed block groups: False
30 Total raw filesystem size: 3.18TiB
31 Device sizes:
32 Device 1: 1.82TiB
33 Device 2: 465.66GiB
34 Device 3: 931.32GiB
35 Metadata to data ratio: 1:200
36 Estimated virtual space to use for metadata: 7.00GiB
37 Estimated virtual space to use for data: 1.36TiB
38 Total unallocatable raw amount: 465.66GiB
39 Unallocatable raw bytes per device:
40 Device 1: 465.66GiB
41 Device 2: 0.00B
42 Device 3: 0.00B
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44 Note that most physical disk vendors specify their sizes in GB or TB
45 for deceptive marketing reasons, while partitions created in your
46 average partition table or with lvm2 etc... are usally using MiB, GiB
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51 -h, --help
52 Show the built-in help message and exit.
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54 -m, --metadata PROFILE
55 Metadata profile, values like for data profile.
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57 -d, --data PROFILE
58 Data profile, raid0, raid1, raid5, raid6, raid10, dup or single.
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60 -M, --mixed
61 Use mixed block groups (data and metadata profile must match).
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63 -r, --ratio RATIO
64 Data to metadata ratio, e.g. 200, which means allocate 0.5% for
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69 This program is an example of what can be done using the python-btrfs
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72 Source and documentation on github: https://github.com/knorrie/python-
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77 2018 BTRFS-SPACE-CALCULATOR(1)