xstat_fs_test: 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/xstat_fs_test - from package: openafs-client

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

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