crsh: 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/crsh - from package: clusterssh

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

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