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BTRFS-DEVICE(8) | Btrfs Manual | BTRFS-DEVICE(8) |
NAME¶
btrfs-device - control btrfs devicesSYNOPSIS¶
btrfs device <subcommand> <args>DESCRIPTION¶
btrfs device is used to control the btrfs devices, since btrfs can be used across several devices, btrfs device is used for multiple device management.DEVICE MANAGEMENT¶
Btrfs filesystem is capable to manage multiple devices. Btrfs filesystem uses different profiles to manage different RAID level, and use balance to rebuild chunks, also devices can be added/removed/replace online. ProfileBtrfs filesystem uses data/metadata profiles to manage
allocation/duplication mechanism.
Profiles like RAID level can be assigned to data and metadata separately.
See mkfs.btrfs(8) for more details.
RAID level
Btrfs filesystem supports most of the standard RAID
level: 0/1/5/6/10.
RAID levels can be assigned at mkfs time or online.
See mkfs.btrfs(8) for mkfs time RAID level assign and
btrfs-balance(8) for online RAID level assign.
Note
Since btrfs is under heavy development especially the RAID5/6 support, it is
highly recommended to read the follow btrfs wiki page to get more
updated details on RAID5/6:
https://btrfs.wiki.kernel.org/index.php/RAID56
Balance
btrfs-balance(8) subcommand can be used to balance
or rebuild chunks to the desired profile.
Due to the fact that balance can rebuild/recovery chunks according to its RAID
duplication if possible, so when using RAID1/5/6/10 with some devices failed
and you just added a new device to btrfs using btrfs-device(8), you
should run btrfs-balance(8) to rebuild the chunks.
See btrfs-balance(8) for more details.
Device add/remove/replace
Device can be added/removed using btrfs-replace(8)
subcommand and replaced using btrfs-replace(8).
When device is removed or replaced, btrfs will do the chunk rebuild if needed.
See btrfs-replace(8) and this man page for more details.
SUBCOMMAND¶
add [-Kf] <dev> [<dev>...] <path>Add device(s) to the filesystem identified by
<path>.
If applicable, a whole device discard (TRIM) operation is performed.
Options
-K|--nodiscard
delete <dev> [<dev>...] <path>
do not perform discard by default
-f|--force
force overwrite of existing filesystem on the given
disk(s)
Remove device(s) from a filesystem identified by
<path>.
scan [(--all-devices|-d)|<device>
[<device>...]]
Scan devices for a btrfs filesystem.
If one or more devices are passed, these are scanned for a btrfs filesystem. If
no devices are passed, btrfs uses block devices containing btrfs filesystem as
listed by blkid. Finally, if --all-devices or -d is passed, all
the devices under /dev are scanned.
ready <device>
Check device to see if it has all of it’s devices
in cache for mounting.
stats [-z] <path>|<device>
Read and print the device IO stats for all devices of the
filesystem identified by <path> or for a single
<device>.
Options
-z
Reset stats to zero after reading them.
EXIT STATUS¶
btrfs device 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), btrfs-replace(8), btrfs-balance(8)11/22/2014 | Btrfs v3.17 |