grsync: 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/grsync - from package: grsync

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

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