slonik_create_set: 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_create_set - from package: slony1-2-bin

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