pcp-atopsar: 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/pcp-atopsar - from package: pcp-system-tools

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

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