# df

_Peios / Using Peios / Peiosutils / Files and directories_

> Report how much space each file system has and how much of it is free.

`df` — "disk free" — reports, for each file system, how much space it has and how much is still available.

```
df [options] [file...]
```

With no arguments, `df` reports on every mounted file system. Given a `file`, it reports on the one file system that file lives on.

```
$ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda2       456G  198G  235G  46% /
/dev/sda1       511M   12M  499M   3% /boot
```

## The default columns

Each line is one file system:

- **Filesystem** — the device or source backing it.
- **Size** — its total capacity.
- **Used** — space in use.
- **Avail** — space still available.
- **Use%** — used space as a percentage.
- **Mounted on** — where it is attached in the directory tree.

## Choosing the units

By default sizes are shown in blocks. These options change that.

| Option | Effect |
|---|---|
| `-h`, `--human-readable` | Show sizes with unit suffixes — `456G`, `12M` — using powers of 1024. |
| `-H`, `--si` | Likewise, but using powers of 1000. |
| `-B`, `--block-size=SIZE` | Show sizes scaled to `SIZE` — `-BM` reports in megabytes. |
| `-k` | Use 1024-byte blocks. |

## Choosing what to report

| Option | Effect |
|---|---|
| `-a`, `--all` | Include dummy and otherwise-hidden file systems that `df` would normally skip. |
| `-l`, `--local` | Report only local file systems, skipping network-mounted ones. |
| `-t`, `--type=TYPE` | Report only file systems of type `TYPE`. |
| `-x`, `--exclude-type=TYPE` | Report everything *except* file systems of type `TYPE`. |
| `--total` | Add a final line giving the grand total across everything reported. |

## Changing the output

| Option | Effect |
|---|---|
| `-i`, `--inodes` | Report inode counts — total, used, and free — instead of block space. A file system can run out of inodes while it still has space. |
| `-T`, `--print-type` | Add a column showing each file system's type. |
| `--output[=LIST]` | Replace the default columns with exactly the fields named in `LIST`. With no list, print every available field. |
| `-P`, `--portability` | Use a fixed, simple column layout that does not wrap a long device name onto its own line. |

## Sync behaviour

| Option | Effect |
|---|---|
| `--sync` | Flush pending writes before reading the usage figures, for the most up-to-date numbers. |
| `--no-sync` | Do not flush first. This is the default and is faster. |

## Exit status

| Code | Meaning |
|---|---|
| `0` | The report was produced. |
| `1` | A failure — for example, a named file does not exist, or the table of file systems could not be read. |

Related content:

- [du](/peios/using-peios/peiosutils/files-and-directories/du.md)
- [Files and directories](/peios/using-peios/peiosutils/files-and-directories/overview.md)