btrfs-space-calculator

BTRFS-SPACE-CALCULATOR(1) Btrfs Space Calculator BTRFS-SPACE-CALCULATOR(1)

NAME

   btrfs-space-calculator - calculate usable and wasted space

SYNOPSIS

   btrfs-space-calculator [args] sizes

DESCRIPTION

   The btrfs-space-calculator program shows the amount of allocatable space on btrfs physical and virtual level, and the amount of unallocatable space resulting
   from having differently sized block devices added to the filesystem.

   In a btrfs filesystem, raw storage is shared by data of different types (System, MetaData and Data) and profiles (e.g. single, DUP, RAID1). Also, a
   filesystem can have multiple block devices of different sizes attached.

   An example:

       -$ btrfs-space-calculator -m raid1 -d raid1 2TB 500G 1TB
       Target metadata profile: RAID1
       Target data profile: RAID1
       Mixed block groups: False
       Total raw filesystem size: 3.18TiB
       Device sizes:
         Device 1: 1.82TiB
         Device 2: 465.66GiB
         Device 3: 931.32GiB
       Metadata to data ratio: 1:200
       Estimated virtual space to use for metadata: 7.00GiB
       Estimated virtual space to use for data: 1.36TiB
       Total unallocatable raw amount: 465.66GiB
       Unallocatable raw bytes per device:
         Device 1: 465.66GiB
         Device 2: 0.00B
         Device 3: 0.00B

   Note that most physical disk vendors specify their sizes in GB or TB, while partitions created in your average partition table or with lvm2 etc... are
   usually using MiB, GiB and TiB.

OPTIONS

   -h, --help
          Show the built-in help message and exit.

   -m, --metadata PROFILE
          Metadata profile, values like for data profile.

   -d, --data PROFILE
          Data profile, raid0, raid1, raid5, raid6, raid10, dup or single.

   -M, --mixed
          Use mixed block groups (data and metadata profile must match).

   -r, --ratio RATIO
          Data to metadata ratio, e.g. 200 (the default), which means allocate 0.5% for metadata. Setting this ratio only makes sense for non-mixed filesystems.
          When using this option in combination with -M, it will be ignored.

SEE ALSO

   This program is an example of what can be done using the python-btrfs library.

   Source and documentation on github: https://github.com/knorrie/python-btrfs

                                                                            2018                                                       BTRFS-SPACE-CALCULATOR(1)