f5rancid: 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 Debian possible default full paths are:

/usr/lib/rancid/bin/f5rancid - from package: rancid

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

Error in other languages:
f5rancid: bevel nie gevind nie
f5rancid: comandă negăsită
f5rancid: comando não encontrado
f5rancid: commande introuvable
f5rancid: command not found
f5rancid: käsku ei ole
f5rancid: không tìm thấy lệnh
f5rancid: komanda nerasta
f5rancid: Kommando nicht gefunden.
f5rancid: kommandot finns inte
f5rancid: komut yok
f5rancid: nie znaleziono polecenia
f5rancid: níor aimsíodh an t-ordú
f5rancid: no se encontró la orden
f5rancid: no s'ha trobat l'ordre
f5rancid: opdracht niet gevonden
f5rancid: parancs nem található
f5rancid: perintah tidak ditemukan
f5rancid: príkaz nenájdený
f5rancid: příkaz nenalezen
f5rancid: команда не найдена
f5rancid: командата не е открита
f5rancid: 命令找不到
f5rancid: コマンドが見つかりません