Dentro do contexto de -o
ou Mount Options, r
não é equivalente a 'somente leitura'; na verdade, nem existe. Você precisa usar ro
- o comando completo se torna isto: mount -o remount,ro /dev/sdb2
O único local r
existe como uma opção para mount
é como um argumento e não como uma opção de montagem.
Na manpage do mount
, eu tirei algumas seções informativas aqui para você. Os comentários #
-preceeded são meus e NÃO da página manpage.
# 'mount' command arguments (NOT mount options, which are passed via '-o'!)
-r, --read-only
Mount the filesystem read-only. A synonym is -o ro.
-o, --options opts
Options are specified with a -o flag followed by a comma sepa‐
rated string of options. For example:
mount LABEL=mydisk -o noatime,nouser
# FILESYSTEM INDEPENDENT MOUNT OPTIONS
remount
Attempt to remount an already-mounted filesystem. This is com‐
monly used to change the mount flags for a filesystem, espe‐
cially to make a readonly filesystem writable. It does not
change device or mount point.
The remount functionality follows the standard way how the mount
command works with options from fstab. It means the mount com‐
mand doesn't read fstab (or mtab) only when a device and dir are
fully specified.
mount -o remount,rw /dev/foo /dir
After this call all old mount options are replaced and arbitrary
stuff from fstab is ignored, except the loop= option which is
internally generated and maintained by the mount command.
mount -o remount,rw /dir
After this call mount reads fstab (or mtab) and merges these
options with options from command line ( -o ).
ro Mount the filesystem read-only.
rw Mount the filesystem read-write.