rcs2log: 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/rcs2log - from package: cvs

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

Error in other languages:
rcs2log: bevel nie gevind nie
rcs2log: comandă negăsită
rcs2log: comando não encontrado
rcs2log: commande introuvable
rcs2log: command not found
rcs2log: käsku ei ole
rcs2log: không tìm thấy lệnh
rcs2log: komanda nerasta
rcs2log: Kommando nicht gefunden.
rcs2log: kommandot finns inte
rcs2log: komut yok
rcs2log: nie znaleziono polecenia
rcs2log: níor aimsíodh an t-ordú
rcs2log: no se encontró la orden
rcs2log: no s'ha trobat l'ordre
rcs2log: opdracht niet gevonden
rcs2log: parancs nem található
rcs2log: perintah tidak ditemukan
rcs2log: príkaz nenájdený
rcs2log: příkaz nenalezen
rcs2log: команда не найдена
rcs2log: командата не е открита
rcs2log: 命令找不到
rcs2log: コマンドが見つかりません