---
name: "btrfs-map-logical"
section: "8"
platform: "linux"
package: "btrfs-progs"
version: "7.3-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/btrfs-map-logical"
---

# btrfs-map-logical(8)

map btrfs logical extent to physical extent

## 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)](/mkfs.btrfs/8.md) \<\>