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BTRFS-FILESYSTEM(8) | Btrfs Manual | BTRFS-FILESYSTEM(8) |
NAME¶
btrfs-filesystem - control btrfs filesystemSYNOPSIS¶
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
If conflicting options are passed, the last one takes precedence.
show
[--mounted|--all-devices|<path>|<uuid>|<device>|
<label>]
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
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
resize
[<devid>:]<size>[gkm]|[<devid>:]max
<path>
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.
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),11/22/2014 | Btrfs v3.17 |