fsck.nfs: 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 Debian possible default full paths are:

/sbin/fsck.nfs - from package: initscripts

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

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