1BTRFS-SPACE-CALCULATOR(1)   Btrfs Space Calculator   BTRFS-SPACE-CALCULATOR(1)
2
3
4

NAME

6       btrfs-space-calculator - calculate usable and wasted space
7
8

SYNOPSIS

10       btrfs-space-calculator [args] sizes
11
12

DESCRIPTION

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.
18
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
22       attached.
23
24       An example:
25
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
43
44       Note that most physical disk vendors specify their sizes in GB or TB,
45       while partitions created in your average partition table or with lvm2
46       etc... are usually using MiB, GiB and TiB.
47
48

OPTIONS

50       -h, --help
51              Show the built-in help message and exit.
52
53       -m, --metadata PROFILE
54              Metadata profile, values like for data profile.
55
56       -d, --data PROFILE
57              Data profile, raid0, raid1, raid5, raid6, raid10, dup or single.
58
59       -M, --mixed
60              Use mixed block groups (data and metadata profile must match).
61
62       -r, --ratio RATIO
63              Data to metadata ratio, e.g. 200 (the default), which means
64              allocate 0.5% for metadata. Setting this ratio only makes sense
65              for non-mixed filesystems. When using this option in combination
66              with -M, it will be ignored.
67
68

SEE ALSO

70       This program is an example of what can be done using the python-btrfs
71       library.
72
73       Source and documentation on github: https://github.com/knorrie/python-
74       btrfs
75
76
77
78                                     2018            BTRFS-SPACE-CALCULATOR(1)
Impressum