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diff --git a/Documentation/btrfs-filesystem.asciidoc b/Documentation/btrfs-filesystem.asciidoc new file mode 100644 index 00000000..cefdc8ea --- /dev/null +++ b/Documentation/btrfs-filesystem.asciidoc @@ -0,0 +1,169 @@ +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|--human-readable:::: +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. + +*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>[kKmMgGtTpPeE]:::: +defragment only from byte <start> onward +-l <len>[kKmMgGtTpPeE]:::: +defragment only up to <len> bytes +-t <size>[kKmMgGtTpPeE]:::: +defragment only files at least <size> bytes big ++ +For <start>, <len>, <size> it is possible to append +units designator: \'K', \'M', \'G', \'T', \'P', or \'E', which represent +KiB, MiB, GiB, TiB, PiB, or EiB, respectively. Case does not matter. ++ +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`. + +*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 + +// Some wording are extracted by the resize2fs man page +*resize* [<devid>:][+/-]<size>[kKmMgGtTpPeE]|[<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', \'G', \'T', \'P', or \'E', which represent +KiB, MiB, GiB, TiB, PiB, or EiB, respectively. Case does not matter. ++ +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. + +*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>. + +*usage* [options] <path> [<path>...]:: +Show detailed information about internal filesystem usage. ++ +`Options` ++ +-b|--raw:::: +raw numbers in bytes, without the 'B' suffix +-h|--human-readable:::: +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 +-T:::: +show data in tabular format ++ +If conflicting options are passed, the last one takes precedence. + +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), |