| btrfs-filesystem(8) |
| =================== |
| |
| NAME |
| ---- |
| btrfs-filesystem - control btrfs filesystem |
| |
| SYNOPSIS |
| -------- |
| *btrfs filesystem* <subcommand> <args> |
| |
| DESCRIPTION |
| ----------- |
| *btrfs filesystem* is used to do the filesystem level control jobs, including |
| all the regular filesystem operations like setting/getting label, |
| resizing, defragment. |
| |
| SUBCOMMAND |
| ---------- |
| *df* [options] <path>:: |
| Show space usage information for a mount point. |
| + |
| `Options` |
| + |
| -b|--raw:::: |
| raw numbers in bytes, without the 'B' suffix |
| -h:::: |
| print human friendly numbers, base 1024, this is the default |
| -H:::: |
| print human friendly numbers, base 1000 |
| --iec:::: |
| select the 1024 base for the following options, according to the IEC standard |
| --si:::: |
| select the 1000 base for the following options, according to the SI standard |
| -k|--kbytes:::: |
| show sizes in KiB, or kB with --si |
| -m|--mbytes:::: |
| show sizes in MiB, or MB with --si |
| -g|--gbytes:::: |
| show sizes in GiB, or GB with --si |
| -t|--tbytes:::: |
| show sizes in TiB, or TB with --si |
| |
| If conflicting options are passed, the last one takes precedence. |
| |
| *show* [--mounted|--all-devices|<path>|<uuid>|<device>|<label>]:: |
| Show the btrfs filesystem with some additional info. |
| + |
| If no option nor <path>|<uuid>|<device>|<label> is passed, btrfs shows |
| information of all the btrfs filesystem both mounted and unmounted. |
| If '--mounted' is passed, it would probe btrfs kernel to list mounted btrfs |
| filesystem(s); |
| If '--all-devices' is passed, all the devices under /dev are scanned; |
| otherwise the devices list is extracted from the /proc/partitions file. |
| |
| *sync* <path>:: |
| Force a sync for the filesystem identified by <path>. |
| |
| *defragment* [options] <file>|<dir> [<file>|<dir>...]:: |
| Defragment file data and/or directory metadata *online*. |
| + |
| If '-r' is passed, files in dir will be defragmented recursively. |
| The start position and the number of bytes to defragment can be specified by |
| start and len using '-s' and '-l' options below. |
| Any extent bigger than threshold given by '-t' option, will be considered |
| already defragged. |
| Use 0 to take the kernel default. |
| You can also turn on compression in defragment operations. |
| + |
| `Options` |
| + |
| -v:::: |
| be verbose |
| -c:::: |
| compress file contents while defragmenting |
| -r:::: |
| defragment files recursively |
| -f:::: |
| flush filesystem after defragmenting |
| -s <start>:::: |
| defragment only from byte <start> onward |
| -l <len>:::: |
| defragment only up to <len> bytes |
| -t <size>:::: |
| defragment only files at least <size> bytes big |
| + |
| For <start>, <len>, <size> it is possible to append a suffix |
| like 'k' for 1 KBytes, 'm' for 1 MBytes... |
| + |
| WARNING: defragmenting with kernels up to 2.6.37 will unlink COW-ed copies of data, |
| don't use it if you use snapshots, have de-duplicated your data or made |
| copies with `cp --reflink`. |
| |
| // Some wording are extracted by the resize2fs man page |
| *resize* [<devid>:][+/-]<size>[gkm]|[<devid>:]max <path>:: |
| Resize a filesystem identified by <path> for the underlying device |
| devid *online*. + |
| The devid can be found with *btrfs filesystem show* and |
| defaults to 1 if not specified. |
| The <size> parameter specifies the new size of the filesystem. |
| If the prefix + or - is present the size is increased or decreased |
| by the quantity <size>. |
| If no units are specified, the unit of the <size> parameter defaults to |
| bytes. Optionally, the size parameter may be suffixed by one of the following |
| units designators: \'K\', \'M', or \'G', kilobytes, megabytes, or gigabytes, |
| respectively. |
| + |
| If \'max' is passed, the filesystem will occupy all available space on the |
| device devid. |
| + |
| The resize command does not manipulate the size of underlying |
| partition. If you wish to enlarge/reduce a filesystem, you must make sure you |
| can expand the partition before enlarging the filesystem and shrink the |
| partition after reducing the size of the filesystem. This can done using |
| `fdisk`(8) or `parted`(8) to delete the existing partition and recreate |
| it with the new desired size. When recreating the partition make sure to use |
| the same starting disk cylinder as before. |
| |
| *label* [<dev>|<mountpoint>] [<newlabel>]:: |
| Show or update the label of a filesystem. |
| + |
| [<device>|<mountpoint>] is used to identify the filesystem. |
| If a newlabel optional argument is passed, the label is changed. |
| NOTE: the maximum allowable length shall be less than 256 chars |
| |
| EXIT STATUS |
| ----------- |
| *btrfs filesystem* returns a zero exit status if it succeeds. Non zero is |
| returned in case of failure. |
| |
| AVAILABILITY |
| ------------ |
| *btrfs* is part of btrfs-progs. |
| Please refer to the btrfs wiki http://btrfs.wiki.kernel.org for |
| further details. |
| |
| SEE ALSO |
| -------- |
| `mkfs.btrfs`(8), |
