storeBackupMount: 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/storeBackupMount - from package: storebackup
/usr/share/storebackup/bin/storeBackupMount - from package: storebackup

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

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