cgclassify: 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:

/bin/cgclassify - from package: libcgroup

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

On Debian possible default full paths are:

/usr/bin/cgclassify - from package: cgroup-tools

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

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