Data copy to USB fails.

[protocoder]

Reporting bug in copying files or images to USB flash disk.

Environment:

Salix Lxde installed from Live Disk.
Test Object: USB TS128MJFLASHA USB device.

Test 1: copy a image, I tried to copy gparted.jpeg to USB from Salix Lxde both a. Linux drive and b. NTFS windows partition drive from My documents and using terminal. (configured to assess the windows drive from Salix).

Result: The copy appears successful. Remove the USB and Insert back and notice that data isn't there. Copied correctly is false confirmation until USB is put back.. It got me crazy for a while.

Test 2: Tried Test 1 with data. Copied a folder and repeated Test 1 with same failure.
At this moment, not sure if it happens with just me.

Thanks
Anand

[JRD]

Di you unmount it before removing your USB key ?

[protocoder]

Aha .. you caught me right. I apologize. This is new to me. I am confused, I don't remember unmounting the usb in Ubuntu. So is my understand right, there is no need to mount any devices but need to unmount them.
Thank you very much.
Anand

[Shador]

Actually you do mount them. But file managers usually either mount them as soon as the device is plugged in (e.g. Windows) or they mount the device implicitly when you first try to open it. So you might not always notice it. Thunar for exmple indicates the mount status by changing the devices color/transperency.

[thenktor]

I am confused, I don't remember unmounting the usb in Ubuntu.

You have to unmount your USB disks everywhere if you want your data to be written safely. Also in Ubuntu or Windows.

[protocoder]

Thank you Shador and thenktor,
In theory yes we need to safely remove USB, 80% time when I tried to safely remove, it says busy or some stuff. over many years I just managed to just pull it out ( talking windows). I will double check with Ubuntu again when I find time. A more linux question. So If I want to mount drive, a camera to suck in pictures etc every time do I have to do dmesg etc to find and make mount with that device, oh yeah first creating a directory as su. Is there a easier way. Any configuration in /fstab or whatever directories. Please can you enlighten me on that please. Cheers

[Shador]

A more linux question. So If I want to mount drive, a camera to suck in pictures etc every time do I have to do dmesg etc to find and make mount with that device, oh yeah first creating a directory as su. Is there a easier way. Any configuration in /fstab or whatever directories. Please can you enlighten me on that please

You don't need to do that. Common linux file managers handle all of this implicitly, i.e. creation of a directory in /media, mounting and unmounting implictly and/or through a easy-to use GUI interface.

In theory yes we need to safely remove USB, 80% time when I tried to safely remove, it says busy or some stuff.

It says this because the data is not yet written to the stick. If you pull it out regardless you will at least loose part of the data. Ever seen those pictures which lack the bottom half or some color channel in that half? That's caused by pulling out a USB stick to early.
If that message appears just wait until your file manager indicates the device as unmounted. For Thunar the device is made transparent in the left pane as long as it is unmounted.

[thenktor]

It says this because the data is not yet written to the stick.

Same message appears if some app has files on the USB stick opened for reading