mkfs.hfsplus: command not found

Have You tried accessing the binary with the full path?

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:

/sbin/mkfs.hfsplus - from package: hfsprogs

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