nss-dbtest: 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:

/usr/bin/nss-dbtest - from package: libnss3-tools

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

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