slonik_store_node: 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_store_node - from package: slony1-2-bin

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