Is it possible to mount an entire disk device read only?

[silver.bullet at zoho.com]

On Sun, 06 Sep 2015 20:52:57 +1000, Karl Auer wrote:
>On Sun, 2015-09-06 at 12:48 +0200, silver.bullet at zoho.com wrote:
>> Actually the question is, if you could mount a complete drive instead
>> of individual partitions, resp. if you could mark a whole drive to be
>> read-only, but than to mount the partitions of that drive one by
>> another.
>
>Are you saying it would be nice to be able to mount the entire drive
>read-only, but then mount specific partitions read-write? That would
>defeat the purpose.

No, you mentioned that you know how to mount individual partitions
read-only, but you want to mount a whole drive read-only.

So, how could somebody mount a complete drive, without mounting it by
the individual partitions?

If a drive provides sda1 and sda2, then AFAIK it always needs to mount
sda1 and sda2, it doesn't matter if I mount them read-only or not,
AFAIK I can't mount sda.

mount /dev/sda /mnt-point-sda1 /mnt-point-sda2

;)

IOW I guess you're asking for a flag that prohibits write access. If
so, then the question is, if the drive should be flagged as read-only,
by the drive, so that a multi-boot or external drive connected to
another computer, always is write protected, or should just one install
use the drive read-only?!