BTRFS-REPLACE(8)                        Btrfs Manual                        BTRFS-REPLACE(8)

NAME
       btrfs-replace - replace devices managed by btrfs with other device.

SYNOPSIS
       btrfs replace <subcommand> <args>

DESCRIPTION
       btrfs replace is used to replace btrfs managed devices with other device.

SUBCOMMAND
       cancel <mount_point>
           Cancel a running device replace operation.

       start [-Bfr] <srcdev>|<devid> <targetdev> <path>
           Replace device of a btrfs filesystem.

           On a live filesystem, duplicate the data to the target device which is currently
           stored on the source device. If the source device is not available anymore, or if
           the -r option is set, the data is built only using the RAID redundancy
           mechanisms. After completion of the operation, the source device is removed from
           the filesystem. If the <srcdev> is a numerical value, it is assumed to be the
           device id of the filesystem which is mounted at <path>, otherwise it is the path
           to the source device. If the source device is disconnected, from the system, you
           have to use the devid parameter format. The <targetdev> needs to be same size or
           larger than the <srcdev>.

               Note
               the filesystem has to be resized to fully take advantage of a larger target
               device; this can be achieved with btrfs filesystem resize <devid>:max /path
           Options

           -r
               only read from <srcdev> if no other zero-defect mirror exists. (enable this
               if your drive has lots of read errors, the access would be very slow)

           -f
               force using and overwriting <targetdev> even if it looks like it contains a
               valid btrfs filesystem.

               A valid filesystem is assumed if a btrfs superblock is found which contains a
               correct checksum. Devices that are currently mounted are never allowed to be
               used as the <targetdev>.

           -B
               no background replace.

       status [-1] <mount_point>
           Print status and progress information of a running device replace operation.

           Options

           -1
               print once instead of print continuously until the replace operation finishes
               (or is cancelled)

EXIT STATUS
       btrfs replace 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-device(8),

Btrfs v4.20.1                            01/23/2019                         BTRFS-REPLACE(8)

usage: btrfs replace <command> [<args>]

    btrfs replace start [-Bfr] <srcdev>|<devid> <targetdev> <mount_point>
        Replace device of a btrfs filesystem.
    btrfs replace status [-1] <mount_point>
        Print status and progress information of a running device replace
    btrfs replace cancel <mount_point>
        Cancel a running device replace operation.

replace a device in the filesystem