cvs: 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/cvs - from package: cvs

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

On Debian possible default full paths are:

/usr/bin/cvs - from package: cvs

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

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