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https://github.com/kdave/btrfs-progs
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85691ebeac
Allow the specification of the filesystem UUID at mkfs time. Non-unique unique IDs are rejected. This includes attempting to re-mkfs with the same UUID; if you really want to do that, you can mkfs with a new UUID, then re-mkfs with the one you wanted. (Implemented only for mkfs.btrfs, not btrfs-convert). Signed-off-by: Eric Sandeen <sandeen@redhat.com> [converted help to asciidoc] Signed-off-by: David Sterba <dsterba@suse.cz>
140 lines
4.0 KiB
Plaintext
140 lines
4.0 KiB
Plaintext
mkfs.btrfs(8)
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=============
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NAME
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----
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mkfs.btrfs - create a btrfs filesystem
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SYNOPSIS
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--------
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*mkfs.btrfs*
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$$[-A|--alloc-start <alloc-start>]$$
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$$[-b|--byte-count <byte-count>]$$
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$$[-d|--data <data-profile>]$$
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$$[-f|--force]$$
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$$[-n|--nodesize <nodesize>]$$
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$$[-l|--leafsize <leafsize>]$$
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$$[-L|--label <label>]$$
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$$[-m|--metadata <metadata profile>]$$
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$$[-M|--mixed]$$
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$$[-s|--sectorsize <sectorsize>]$$
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$$[-r|--rootdir <rootdir>]$$
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$$[-K|--nodiscard]$$
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$$[-O|--features <feature1>[,<feature2>...]]$$
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$$[-U|--uuid <UUID>]$$
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$$[-h]$$
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$$[-V|--version]$$
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$$<device> [<device>...]$$
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DESCRIPTION
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-----------
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*mkfs.btrfs*
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is used to create a btrfs filesystem (usually in a disk partition, or an array
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of disk partitions).
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<device>
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is the special file corresponding to the device (e.g /dev/sdXX ).
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If multiple devices are specified, btrfs is created
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spanning across the specified devices.
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OPTIONS
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-------
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-A|--alloc-start <offset>::
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Specify the offset from the start of the device at which to start allocations
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in this btrfs filesystem. The default value is zero, or the start of the
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device. This option is intended only for debugging filesystem resize
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operations.
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-b|--byte-count <size>::
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Specify the size of the resultant filesystem. If this option is not used,
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mkfs.btrfs uses all the available storage for the filesystem.
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-d|--data <type>::
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Specify how the data must be spanned across the devices specified. Valid
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values are 'raid0', 'raid1', 'raid5', 'raid6', 'raid10' or 'single'.
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-f|--force::
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Force overwrite when an existing filesystem is detected on the device.
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By default, mkfs.btrfs will not write to the device if it suspects that
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there is a filesystem or partition table on the device already.
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-n|--nodesize <size>
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+
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-l|--leafsize <size>::
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Specify the nodesize, the tree block size in which btrfs stores
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data. The default value is 16KB (16384) or the page size, whichever is
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bigger. Must be a multiple of the sectorsize, but not larger than
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65536. Leafsize always equals nodesize and the options are aliases.
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-L|--label <name>::
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Specify a label for the filesystem.
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+
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NOTE: <name> should be less than 256 characters.
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-m|--metadata <profile>::
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Specify how metadata must be spanned across the devices specified. Valid
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values are 'raid0', 'raid1', 'raid5', 'raid6', 'raid10', 'single' or 'dup'.
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+
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Single device
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will have dup set by default except in the case of SSDs which will default to
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single. This is because SSDs can remap blocks internally so duplicate blocks
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could end up in the same erase block which negates the benefits of doing
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metadata duplication.
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-M|--mixed::
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Mix data and metadata chunks together for more efficient space
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utilization. This feature incurs a performance penalty in
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larger filesystems. It is recommended for use with filesystems
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of 1 GiB or smaller.
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-s|--sectorsize <size>::
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Specify the sectorsize, the minimum data block allocation unit.
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+
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The default
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value is the page size. If the sectorsize differs from the page size, the
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created filesystem may not be mountable by current kernel. Therefore it is not
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recommended to use this option unless you are going to mount it on a system
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with the appropriate page size.
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-r|--rootdir <rootdir>::
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Specify a directory to copy into the newly created btrfs filesystem.
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+
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NOTE: '-r' option is done completely in userland, and don't need root
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privilege to mount the filesystem.
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-K|--nodiscard::
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Do not perform whole device TRIM operation by default.
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-O|--features <feature1>[,<feature2>...]::
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A list of filesystem features turned on at mkfs time. Not all features are
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supported by old kernels.
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+
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To see all features run::::
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mkfs.btrfs -O list-all
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-U|--uuid <UUID>::
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Create the filesystem with the specified UUID, which must not already exist on
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the system.
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-V|--version::
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Print the *mkfs.btrfs* version and exit.
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-h::
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Print help.
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UNIT
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----
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As default the unit is the byte, however it is possible to append a suffix
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to the arguments like 'k' for KBytes, 'm' for MBytes...
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AVAILABILITY
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------------
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*btrfs* is part of btrfs-progs.
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Please refer to the btrfs wiki http://btrfs.wiki.kernel.org for
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further details.
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SEE ALSO
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--------
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`btrfs`(8)
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