pgreplay: 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/pgreplay - from package: pgreplay

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

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