rhevsh: 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/rhevsh - from package: rhevsh

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

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