dosfslabel: 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/dosfslabel - from package: dosfstools

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

On Debian possible default full paths are:

/sbin/dosfslabel - from package: dosfstools

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

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