pmval: 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/pmval - from package: pcp

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

On Debian possible default full paths are:

/usr/bin/pmval - from package: pcp

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

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