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|
btrfs-device(8)
===============
NAME
----
btrfs-device - control btrfs devices
SYNOPSIS
--------
'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.
Profile::
Btrfs 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.
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::::
do not perform discard by default
-f|--force::::
force overwrite of existing filesystem on the given disk(s)
'delete' <dev> [<dev>...] <path>::
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.
'disk-usage' [-b] <path> [<path>..]::
Show which chunks are in a device.
+
If '-b' is given, byte will be set as unit.
'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 exist status if it succeeds. Non zero is
returned in case of failure.
AVAILABILITY
------------
'btrfs' is part of btrfs-progs. Btrfs filesystem is currently under heavy
development,
and not suitable for any uses other than benchmarking and review.
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)
|
