condor_master: 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/sbin/condor_master - from package: condor

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

On Debian possible default full paths are:

/usr/sbin/condor_master - from package: htcondor

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

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