getent: 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:

/usr/bin/getent - from package: glibc-common

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

On Debian possible default full paths are:

/usr/bin/getent - from package: libc-bin

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

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