dosfsck: 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/dosfsck - from package: dosfstools

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

On Debian possible default full paths are:

/sbin/dosfsck - from package: dosfstools

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

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