pdsh: 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 CentOS possible default full paths are:

/usr/bin/pdsh - from package: pdsh

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/pdsh - from package: pdsh

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

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