cgsnapshot: 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/cgsnapshot - from package: libcgroup

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

On Debian possible default full paths are:

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

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

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