glances: 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/glances - from package: glances

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

On Debian possible default full paths are:

/usr/bin/glances - from package: glances

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

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