usn-tombstone-cleanup: 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/sbin/usn-tombstone-cleanup - from package: 389-ds-base

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

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