External drive is being mounted as read-only

[Tim]

Allegedly, on or about 01 September 2014, Sudhir Khanger sent:
> one possibility is that I use same username across systems which might
> have made it possible to mount with RW without superuser privileges. 

Yes, but...  It's not so much the user name that's important, but the
*numerical* user and group ID need to be the same (yes, there are some
systems that can remap names, but it's easier not to have to bother).

On my very old Fedora system, my username of "tim" is user number 500,
on the current version it's user number 1000.  Files are stored against
the user *number*, which gets mapped against a local user name when you
list them to see who owns them.

I could be user "tim" on computer, and user "me" on another, but so long
as they were both user number 1000, file ownership would remain mine.
Conversely, if you have two different users on different computers, but
using the same user numbers, they get access to each others files.
That's a problem that you don't want.

Have a look at the "-n" option with the "ls" command, on various files,
to see this in practice.  e.g. ls -n /home

-- 
[tim at localhost ~]$ uname -rsvp
Linux 3.9.10-100.fc17.x86_64 #1 SMP Sun Jul 14 01:31:27 UTC 2013 x86_64

All mail to my mailbox is automatically deleted, there is no point
trying to privately email me, I will only read messages posted to the
public lists.

George Orwell's '1984' was supposed to be a warning against tyranny, not
a set of instructions for supposedly democratic governments.

ZNQR LBH YBBX