db2ldif: 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/db2ldif - from package: 389-ds-base

You may install the required package with command apt-get install {package}
Error in other languages:
db2ldif: bevel nie gevind nie
db2ldif: comandă negăsită
db2ldif: comando não encontrado
db2ldif: commande introuvable
db2ldif: command not found
db2ldif: käsku ei ole
db2ldif: không tìm thấy lệnh
db2ldif: komanda nerasta
db2ldif: Kommando nicht gefunden.
db2ldif: kommandot finns inte
db2ldif: komut yok
db2ldif: nie znaleziono polecenia
db2ldif: níor aimsíodh an t-ordú
db2ldif: no se encontró la orden
db2ldif: no s'ha trobat l'ordre
db2ldif: opdracht niet gevonden
db2ldif: parancs nem található
db2ldif: perintah tidak ditemukan
db2ldif: príkaz nenájdený
db2ldif: příkaz nenalezen
db2ldif: команда не найдена
db2ldif: командата не е открита
db2ldif: 命令找不到
db2ldif: コマンドが見つかりません