condor_gather_info: 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/condor_gather_info - from package: condor

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

On Debian possible default full paths are:

/usr/bin/condor_gather_info - from package: htcondor

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

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