biber: 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/bin/biber - from package: biber

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

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