# BTRFS-MAP-LOGICAL(8) - man - phpMan

[BTRFS-MAP-LOGICAL(8)](https://www.chedong.com/phpMan.php/man/BTRFS-MAP-LOGICAL/8/markdown)                        Btrfs Manual                        [BTRFS-MAP-LOGICAL(8)](https://www.chedong.com/phpMan.php/man/BTRFS-MAP-LOGICAL/8/markdown)



## NAME
       btrfs-map-logical - map btrfs logical extent to physical extent

## SYNOPSIS
       **btrfs-map-logical** _<options>_ _<device>_

## DESCRIPTION
       **btrfs-map-logical** can be used to find out what the physical offsets are on the mirrors, the
       result is dumped to stdout by default.

       Mainly used for debug purpose.

## OPTIONS
       -l|--logical _<logical_num>_
           Logical extent to map.

       -c|--copy _<copy>_
           Copy of the extent to read(usually 1 or 2).

       -o|--output _<filename>_
           Output file to hold the extent.

       -b|--bytes _<bytes>_
           Number of bytes to read.

## EXIT STATUS
       **btrfs-map-logical** will return 0 if no error happened. If any problems happened, 1 will be
       returned.

## SEE ALSO
       [**mkfs.btrfs**(8)](https://www.chedong.com/phpMan.php/man/mkfs.btrfs/8/markdown)



Btrfs v5.16.2                                02/16/2022                         [BTRFS-MAP-LOGICAL(8)](https://www.chedong.com/phpMan.php/man/BTRFS-MAP-LOGICAL/8/markdown)