Unable to mount USB Flash memory created on CentOS

[Polytropon]

On Fri, 28 Jul 2017 13:22:06 -0400, James B. Byrne via freebsd-questions wrote:
> On my new FreeBSD workstation I am trying to read data off of a USB
> 'key' flash memory stick recorded using rsync on a CentOS-6 system.  I
> was able to do this successfully up until the point that I inserted
> another usb stick.  Now I cannot mount or read either.

Did you unmount the previous stick correctly?

When you say it was "recorded" with CentOS, which file system
has been used? Or is it a "raw" file (no file system at all,
output written directly to the device)?



> I probably made things worse by first removing both keys from the host
> and then deleting the contents of /media.  However, that is done.

That should not be a big problem, as /media is usually populated
automatically by a desktop environment's automounter, or manually
by the system administrator (which implies that you can easily
recreate required mountpoints under /media if you use /etc/fstab
as a template).



> At the moment what happens is that upon insertion the 'computer'
> browser pane will display a filesystem labelled 'USB Drive' but I
> cannot open it for viewing.

Is it empty? When you say it's being opened, I assume this is a
file browser - but from which desktop? They are quite different!

Check things easily: Open a terminal and check the outpuf of

	% mount -v

Is the USB stick (usually /dev/da0 or /dev/da0s1 or something
like that) _really_ mounted?

Check what's on the USB stick, using

	% gpart show da0

where da0 is the device for the USB stick. To check if da0 is
correct, check the last lines of

	% dmesg

It should be easy to identify what the USB stick is.



> Neither does a mount command show in the
> right-click popup menu.

So it probably _is_ mounted. Does the menu show a "detach",
"unoumt" or "eject" entry or symbol?

As I said, don't rely on distracting pictural elements. Query
the OS directly using the command line. It will tell you what
is _really_ happening.



> Rebooting the system does not return the system to its former behaviour.

It _never_ does. ;-)



> How is this fixed?  Is it not possible to have two USB drives mounted
> simulatenously?

You need to provide more information.



-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...