nfswatch: command not found

Have You tried accessing the binary with the full path?

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:

/usr/sbin/nfswatch - from package: nfswatch

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