É o comportamento correto.
Você usa o sinal -f
, que significa:
-f
,--fake
: Causes everything to be done except for the actual system call; if it's not obvious, this ''fakes'' mounting the filesystem. This option is useful in conjunction with the-v
flag to determine what the mount command is trying to do. It can also be used to add entries for devices that were mounted earlier with the-n
option. The-f
option checks for an existing record in/etc/mtab
and fails when the record already exists (with a regular non- fake mount, this check is done by the kernel).
Veja também Remontar um disco ocupado para o modo somente leitura .