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

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