btrfs-map-logical: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/sbin/btrfs-map-logical - from package: btrfs-progs

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/sbin/btrfs-map-logical - from package: btrfs-tools

You may install the required package with command apt-get install {package}

Error in other languages:
btrfs-map-logical: bevel nie gevind nie
btrfs-map-logical: comandă negăsită
btrfs-map-logical: comando não encontrado
btrfs-map-logical: commande introuvable
btrfs-map-logical: command not found
btrfs-map-logical: käsku ei ole
btrfs-map-logical: không tìm thấy lệnh
btrfs-map-logical: komanda nerasta
btrfs-map-logical: Kommando nicht gefunden.
btrfs-map-logical: kommandot finns inte
btrfs-map-logical: komut yok
btrfs-map-logical: nie znaleziono polecenia
btrfs-map-logical: níor aimsíodh an t-ordú
btrfs-map-logical: no se encontró la orden
btrfs-map-logical: no s'ha trobat l'ordre
btrfs-map-logical: opdracht niet gevonden
btrfs-map-logical: parancs nem található
btrfs-map-logical: perintah tidak ditemukan
btrfs-map-logical: príkaz nenájdený
btrfs-map-logical: příkaz nenalezen
btrfs-map-logical: команда не найдена
btrfs-map-logical: командата не е открита
btrfs-map-logical: 命令找不到
btrfs-map-logical: コマンドが見つかりません