schema2ldif: 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/bin/schema2ldif - from package: schema2ldif

You may install the required package with command apt-get install {package}
Error in other languages:
schema2ldif: bevel nie gevind nie
schema2ldif: comandă negăsită
schema2ldif: comando não encontrado
schema2ldif: commande introuvable
schema2ldif: command not found
schema2ldif: käsku ei ole
schema2ldif: không tìm thấy lệnh
schema2ldif: komanda nerasta
schema2ldif: Kommando nicht gefunden.
schema2ldif: kommandot finns inte
schema2ldif: komut yok
schema2ldif: nie znaleziono polecenia
schema2ldif: níor aimsíodh an t-ordú
schema2ldif: no se encontró la orden
schema2ldif: no s'ha trobat l'ordre
schema2ldif: opdracht niet gevonden
schema2ldif: parancs nem található
schema2ldif: perintah tidak ditemukan
schema2ldif: príkaz nenájdený
schema2ldif: příkaz nenalezen
schema2ldif: команда не найдена
schema2ldif: командата не е открита
schema2ldif: 命令找不到
schema2ldif: コマンドが見つかりません