upgradedb: 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/upgradedb - from package: 389-ds-base

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