clvmd: 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/sbin/clvmd - from package: lvm2-cluster

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

On Debian possible default full paths are:

/usr/sbin/clvmd - from package: clvm

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

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