btrfs-balance

TLDR

Show status

$ sudo btrfs balance status path/to/filesystem

Start full balance

$ sudo btrfs balance start path/to/filesystem

Balance underused data chunks

$ sudo btrfs balance start --bg -dusage=15 path/to/filesystem

Balance metadata with limits

$ sudo btrfs balance start -musage=20,limit=10 path/to/filesystem

Convert RAID profile

$ sudo btrfs balance start -dconvert=raid6 -mconvert=raid1c3 path/to/filesystem

Cancel/pause/resume

$ sudo btrfs balance cancel path/to/filesystem

SYNOPSIS

btrfs balance command [OPTIONS] path

DESCRIPTION

btrfs balance redistributes data across devices in a btrfs filesystem. It can rebalance data, convert between RAID profiles, and relocate chunks from specific devices.

PARAMETERS

start

Start a balance operation

status

Show status of running or paused balance

cancel

Cancel a running balance

pause

Pause a running balance

resume

Resume a paused balance

-d filters

Apply filters to data block groups

-m filters

Apply filters to metadata block groups

-s filters

Apply filters to system block groups

--bg, --background

Run in background

usage= percent

Balance chunks with usage below percentage

limit= count

Process at most this many chunks

convert= profile

Convert to specified RAID profile

soft

Skip chunks already matching the target profile

A full balance rewrites all data and is very slow. Use filters to target only necessary chunks. Balance requires free space to relocate data. Converting RAID profiles on a busy system may take a long time.

HISTORY

btrfs balance is part of the btrfs-progs package for managing btrfs filesystems on Linux.