Linux command
btrfs-balance 命令
安全
权限或系统影响较大，执行前请核对目标。
常用示例
Show balance status
sudo btrfs balance status [/mnt/data]
Start a full balance
sudo btrfs balance start [/mnt/data]
Balance underused data chunks
sudo btrfs balance start --bg -dusage=[15] [/mnt/data]
Balance metadata with a chunk limit
sudo btrfs balance start -musage=[20],limit=[10] [/mnt/data]
Convert RAID profile
sudo btrfs balance start -dconvert=[raid6] -mconvert=[raid1c3] [/mnt/data]
Cancel a running balance
sudo btrfs balance cancel [/mnt/data]
说明
btrfs balance redistributes data and metadata across devices in a btrfs filesystem. It operates on block groups (chunks), moving their contents to achieve a more even distribution or to convert between RAID profiles. Common use cases include rebalancing after adding or removing devices, converting from one RAID level to another, and reclaiming space by consolidating partially used chunks. Filters allow targeting specific chunk types (data, metadata, system) and usage thresholds to avoid unnecessary work.
参数
- 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
- devid= _id_
- Balance only chunks on the given device
- drange= _start..end_
- Balance only chunks overlapping byte range
- -f
- Force reducing metadata integrity (e.g., raid1 to single)
FAQ
What is the btrfs-balance command used for?
btrfs balance redistributes data and metadata across devices in a btrfs filesystem. It operates on block groups (chunks), moving their contents to achieve a more even distribution or to convert between RAID profiles. Common use cases include rebalancing after adding or removing devices, converting from one RAID level to another, and reclaiming space by consolidating partially used chunks. Filters allow targeting specific chunk types (data, metadata, system) and usage thresholds to avoid unnecessary work.
How do I run a basic btrfs-balance example?
Run `sudo btrfs balance status [/mnt/data]` in a terminal, then adjust file names, paths, flags, or remote targets for your system.
What does start do in btrfs-balance?
Start a balance operation