The following options apply only to certain file systems:
Programs that do computed lseeks won't like in-kernel text conversion.
Several people have had their data ruined by this translation. Beware!
For file systems mounted in
binary
mode, a conversion tool (fromdos/todos) is available.
The full set of options applied is determined by first extracting the
options for the file system from the
fstab
table, then applying any options specified by the
-o
argument, and finally applying the
-r " or " -w
option.
If the
msdos
file system detects an inconsistency, it reports an error and sets the file
system read-only. The file system can be made writeable again by remounting
it.
One further possible type is a mount via the loop device. For example,
the command
mount /tmp/fdimage /mnt -t msdos -o loop=/dev/loop3,blocksize=1024
will set up the loop device /dev/loop3 to correspond to the file
/tmp/fdimage, and then mount this device on /mnt.
This type of mount knows about three options, namely loop, offset and
encryption, that are really options to
losetup (8).
If no explicit loop device is mentioned (but just an option `-o loop' is given), then
mount
will try to find some unused loop device and use that.
Umount
removes the
special
device, or the device grafted at point
node ,
from the file system tree. It will also free the loop device (if any) associated
with the mount, in case it finds the option `loop=...' in
/etc/mtab .
Any pending loop devices can be freed using `losetup -d', see
losetup (8).
Options for the
umount
command:
Some Linux file systems don't support -o " synchronous" (the ext2fs does support synchronous updates (a la BSD) when mounted with the sync option).
The -o " remount" may not be able to change mount parameters (all ext2fs parameters, except sb , are changeable with a remount, for example, but you can't change gid or umask for the dosfs ).