unlog: 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/unlog - from package: openafs-client

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

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