slonik_print_preamble: 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/slonik_print_preamble - from package: slony1-2-bin

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