pgsnap: command not found

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/pgsnap - from package: pgsnap

You may install the required package with command apt-get install {package}

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