Cannot See USB Memory Devices

[starter]

I am new to the Raspberry Pi and know little about Linux. I am having great difficulty getting usb memory pens or usb hard disks to show on the system. The Raspberry Pi I have bought has the operating system installed and boots into the GUI.
I have the User Guide book by Eben Upton in which it tells me (on page 34) that simply plugging-in a usb memory device LXDE will automatically install the device and present a window titled “Removable Medium is Inserted”. This does not happen.
As an alternate Upton tells me how to mount the device starting with the use of ‘sudo fdisk –l’ to find the device. This does not report any device.
I have also tried using ‘sudo tail –f /var/log/syslog’ and inserting device to see its allocation – a solution I have seen reported by others. This does not report anything useful.
I do notice, however, that if I insert the device before boot-up, it does appear in the /var/disk/by-id folder, but does not seem to be accessible there.
Basically I am stuck! Does anyone have any suggestions? Is my Raspberry Pi faulty? I would be grateful for any help.

[aaa801]

dmesg output after inserting usb?

[malakai]

Are you using a powered hub?

[PS1981]

Can you see it in the File Manager window?

[starter]

Reply to malakai: Yes I am using apowered USB Hub.

Reply to aaa801: There is no change in message output when usb devices inserted. Simply reports failure to read register index and then failure to write register index - both before and after.

Reply to PS1981: I used File Manger to see that devices are reported in /dev/disk/by-id folder. Here it names the device found correctly. I note that I made an error in my earlier post writing /var/disk/by-id, but it is /dev/disk/by-id.

Many thanks for your interest and help.

[jamiesk]

try a lsusb and what does that show ?

mine is ...
root@raspberrypi:/home/pi# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 0424:9512 Standard Microsystems Corp.
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp.
Bus 001 Device 004: ID 050d:0084 Belkin Components F8T003v2 Bluetooth
Bus 001 Device 005: ID 0403:6001 Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC
root@raspberrypi:/home/pi#

[starter]

Thank you Jamiesk. Yes I get a similar output but with devices mentioned.
This led me to re-look at advice earlier and I can see both devices in File Manager under Computer.
Please excuse me, I am really new to this and I didn't know that compter was, say, the equivalent of My Computer on Windows.
So . . . both devices are there but how do I access them? They show no owner or group and no permissions, so how do I mount them??

Many thanks for all help. I feel that I am getting somewhere . . . but not there yet!!

[jamiesk]

I dont know if the rPi automounts USB. Try a "df -h"

root@raspberrypi:/home/pi# df -h
Filesystem Size Used Avail Use% Mounted on
rootfs 3.7G 1.5G 2.0G 44% /
/dev/root 3.7G 1.5G 2.0G 44% /
devtmpfs 243M 0 243M 0% /dev
tmpfs 49M 228K 49M 1% /run
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 98M 0 98M 0% /run/shm
/dev/mmcblk0p1 56M 17M 40M 30% /boot
root@raspberrypi:/home/pi#

this is the standard layout for a 4G SD card.

If you have entries like /dev/sda then the USB stick is already mounted, and the end of the line should show where its mounted.

If not then you need to manually mount it. have a look at http://linuxcommando.blogspot.co.uk/200 ... -from.html

[sdjf]

You look for a line in the dmesg output that tells you what the mount point would be of the media that you inserted.

Look for something like "sda: sda1" or "sdb: sdb1", something starting with sd and a letter right after that.

from commandline then issue, for example:

mount /media/sda1
or if you need to us sudo
sudo mount /media/sda1

And see the answer to that. you may need to add the device reference to /etc/fstab, I have no idea what tabs you would use in a GUI to do that.

[starter]

I am posting this query a second time.
I am having great problems attempting to mount a usb memory stick.
It is a PNY 16GB usb memory.
I had good advice yesterday and am grateful to those who offered help. I can now see that after boot-up the raspberry pi sees the device in File Manager in My Computer. When I right click and look at properties I see the following:

Pny USB 2.0 FD
Location: My Computer
File Type: Mount Point
Open with: File Manager

At the command line when I run “dmesg | more” and look down the output I find the following at one point:

scsi 0:0:0:0 Direct-Access pny USB 2.0 FD 1.00 PQ: 0 ANSI: 4
sd 0:0:0:0 [sda] 31334400 521-byte logical blocks: (16.0 GB/14.9 GiB)
sd 0:0:0:0 [sda] Write Protect is off
sd 0:0:0:0 [sda] Mode Sense: 2f 00 00 00
sd 0:0:0:0 [sda] Write cache: disabled, reda cache: enabled, doesn’t support DPO or FUA
sda: sda1
sd 0:0:0:0 [sda] Attached scsi removeable disk

My question is: is this telling me that the device is sda1??

I have previously created a folder /media/usbdrive as instructed in ‘User Guide’ book and given permissions

Now when I try to mount sda1 using:

sudo mount /dev/sda1 /media/usbdrive -o=rw as instructed in ‘User Guide’ book

I get: mount: optmap.c:199: mnt_optmap_get_entry: Assertion ‘namelen’ failed. Aborted.

Which really does not help!!

Can anyone suggest where things are going wrong??

[gourmetbreakfast]

Starter - I found your post because I am having the exact same problem following along in the same book.

I was able to mount my USB drive using the link provided by jamiesk: http://linuxcommando.blogspot.co.uk/200 ... -from.html

[DirkS]

Now when I try to mount sda1 using:

sudo mount /dev/sda1 /media/usbdrive -o=rw as instructed in ‘User Guide’ book

I get: mount: optmap.c:199: mnt_optmap_get_entry: Assertion ‘namelen’ failed. Aborted.

I think the equal sign is the problem here and this should work:

Code: Select all

sudo mount /dev/sda1 /media/usbdrive -o rw

Gr.
Dirk.

[gourmetbreakfast]

Thanks, DirkS. That's the second typo I've noticed in this book so far. :-/ The other has it "cmdline.xt" instead of "commandline.txt" on page 54, about the emergency kernel.

In spite of that, I'm finding the book pretty useful as a Linux newbie.

Now when I try to mount sda1 using:

sudo mount /dev/sda1 /media/usbdrive -o=rw as instructed in ‘User Guide’ book

I get: mount: optmap.c:199: mnt_optmap_get_entry: Assertion ‘namelen’ failed. Aborted.

I think the equal sign is the problem here and this should work:

Code: Select all

sudo mount /dev/sda1 /media/usbdrive -o rw

Gr.
Dirk.

[liz]

If you do spot errata in the book, would you mind making a note of them and emailing me? I can then forward any problems to the publisher, who will be addressing them in the second edition.

[Jim JKla]

So now we proof read the book as well.

Do you trust us this much?

[byque]

DirkS thank you! I bought the kindle edition and it has the same error. Glad you find the solution. I just registered to say thank you.

Have a nice day,

Byron

[boilingfrog]

I also fell foul of this typo, the weird thing being that it did work once, but not subsequently???

[ehbowenbo]

I know I'm late to this party, but this just happened to me and this is one of the threads that I found trying to figure it out.

I use my Raspberry Pi as an OpenElec media client 364 days out of the year. But one day at the end of the year I shut it down, swap out the SD card, boot it up and run apt-get update and upgrade all...then disconnect it from the network and use it to renew my OpenSSL keys for the year. Well, as part of that renewal I finished, shut it down...and then realized that I had forgotten to update my certificate revocation list.

I plugged it back in, rebooted...and for the life of me I couldn't get it to recognize or mount the USB stick with my certificate files. I puzzled with it, did a few online searches (including this one)...and then realized that with the Pi disconnected from the network it could not update its internal clock upon the restart. I shut it down, connected it to the network, restarted it again...and this time everything worked.