pmcd: 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/libexec/pcp/bin/pmcd - from package: pcp

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

On Debian possible default full paths are:

/usr/lib/pcp/bin/pmcd - from package: pcp

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

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