knowledge/technology/linux/filesystems/MergerFS Tools.md

---
obj: application
repo: https://github.com/trapexit/mergerfs-tools
---

# [MergerFS](MergerFS.md) Tools

## mergerfs.ctl
A wrapper around mergerfs.

```shell
$ mergerfs.ctl -h
usage: mergerfs.ctl [-h] [-m MOUNT] {add,remove,list,get,set,info} ...

positional arguments:
  {add,remove,list,get,set,info}

optional arguments:
  -h, --help            show this help message and exit
    -m MOUNT, --mount MOUNT
                            mergerfs mount to act on
$ mergerfs.ctl info
- mount: /storage
  version: 2.14.0
  pid: 1234
  srcmounts:
    - /mnt/drive0
    - /mnt/drive1
$ mergerfs.ctl -m /storage add path /mnt/drive2
$ mergerfs.ctl info
- mount: /storage
  version: 2.14.0
  pid: 1234
  srcmounts:
    - /mnt/drive0
    - /mnt/drive1
    - /mnt/drive2
```

## mergerfs.fsck
Audits permissions and ownership of files and directories in a mergerfs mount and allows for manual and automatic fixing of them.

```shell
$ mergerfs.fsck -h
usage: mergerfs.fsck [-h] [-v] [-s] [-f {manual,newest,nonroot}] dir

audit a mergerfs mount for inconsistencies

positional arguments:
  dir                   starting directory

  optional arguments:
    -h, --help            show this help message and exit
    -v, --verbose         print details of audit item
    -s, --size            only consider if the size is the same
    -f {manual,newest,nonroot}, --fix {manual,newest,nonroot}
                          fix policy
$ mergerfs.fsck -v -f manual /path/to/dir
```

## mergerfs.dup
Duplicates files & directories across branches in a pool. The file selected for duplication is picked by the `dup` option. Files will be copied to drives with the most free space. Deleted from others if `prune` is enabled.

```shell
usage: mergerfs.dup [<options>] <dir>

Duplicate files & directories across multiple drives in a pool.
Will print out commands for inspection and out of band use.

positional arguments:
  dir                    starting directory

optional arguments:
  -c, --count=           Number of copies to create. (default: 2)
  -d, --dup=             Which file (if more than one exists) to choose to
                         duplicate. Each one falls back to `mergerfs` if
                         all files have the same value. (default: newest)
                         * newest   : file with largest mtime
                         * oldest   : file with smallest mtime
                         * smallest : file with smallest size
                         * largest  : file with largest size
                         * mergerfs : file chosen by mergerfs' getattr
  -p, --prune            Remove files above `count`. Without this enabled
                         it will update all existing files.
  -e, --execute          Execute `rsync` and `rm` commands. Not just
                         print them.
  -I, --include=         fnmatch compatible filter to include files.
                         Can be used multiple times.
  -E, --exclude=         fnmatch compatible filter to exclude files.
                         Can be used multiple times.
```

## mergerfs.dedup
Finds and removes duplicate files across mergerfs pool's branches. Use the `ignore`, `dedup`, and `strict` options to target specific use cases.

```shell
usage: mergerfs.dedup [<options>] <dir>

Remove duplicate files across branches of a mergerfs pool. Provides
multiple algos for determining which file to keep and what to skip.

positional arguments:
  dir                    Starting directory

optional arguments:
  -v, --verbose          Once to print `rm` commands
                         Twice for status info
                         Three for file info
  -i, --ignore=          Ignore files if... (default: none)
                         * same-size      : have the same size
                         * different-size : have different sizes
                         * same-time      : have the same mtime
                         * different-time : have different mtimes
                         * same-hash      : have the same md5sum
                         * different-hash : have different md5sums
  -d, --dedup=           What file to *keep* (default: newest)
                         * manual        : ask user
                         * oldest        : file with smallest mtime
                         * newest        : file with largest mtime
                         * largest       : file with largest size
                         * smallest      : file with smallest size
                         * mostfreespace : file on drive with most free space
  -s, --strict           Skip dedup if all files have same value.
                         Only applies to oldest, newest, largest, smallest.
  -e, --execute          Will not perform file removal without this.
  -I, --include=         fnmatch compatible filter to include files.
                         Can be used multiple times.
  -E, --exclude=         fnmatch compatible filter to exclude files.
                         Can be used multiple times.

# mergerfs.dedup /path/to/dir
# Total savings: 10.0GB

# mergerfs.dedup -e -d newest /path/to/dir
mergerfs.dedup -v -d newest /media/tmp/test
rm -vf /mnt/drive0/test/foo
rm -vf /mnt/drive1/test/foo
rm -vf /mnt/drive2/test/foo
rm -vf /mnt/drive3/test/foo
# Total savings: 10.0B
```

## mergerfs.balance
Will move files from the most filled drive (percentage wise) to the least filled drive. Will do so till the most and least filled drives come within a user defined percentage range (defaults to 2%).

```shell
usage: mergerfs.balance [-h] [-p PERCENTAGE] [-i INCLUDE] [-e EXCLUDE]
                        [-I INCLUDEPATH] [-E EXCLUDEPATH] [-s EXCLUDELT]
                        [-S EXCLUDEGT]
                        dir

balance files on a mergerfs mount based on percentage drive filled

positional arguments:
  dir                   starting directory

optional arguments:
  -h, --help            show this help message and exit
  -p PERCENTAGE         percentage range of freespace (default 2.0)
  -i INCLUDE, --include INCLUDE
                        fnmatch compatible file filter (can use multiple
                        times)
  -e EXCLUDE, --exclude EXCLUDE
                        fnmatch compatible file filter (can use multiple
                        times)
  -I INCLUDEPATH, --include-path INCLUDEPATH
                        fnmatch compatible path filter (can use multiple
                        times)
  -E EXCLUDEPATH, --exclude-path EXCLUDEPATH
                        fnmatch compatible path filter (can use multiple
                        times)
  -s EXCLUDELT          exclude files smaller than <int>[KMGT] bytes
  -S EXCLUDEGT          exclude files larger than <int>[KMGT] bytes

# mergerfs.balance /media
from: /mnt/drive1/foo/bar
to:   /mnt/drive2/foo/bar
rsync ...
```