Raspberry Pi Forums

Hi all,

I have been having some problems related to usb devices with the pi.
I got this usb key to store media files for watching on the pi:
http://www.amazon.co.uk/SanDisk-Cruzer- ... f_dp_p_t_4

When the usb key is plugged in sometimes during boot it does not come up in /dev/sda
(I can tell as I have it set to mount to a particular dir and this fails)

Other times it does but after using it for a short period (e.g. reading a file, doing any of the commands ls,mv,cp etc)
the following error pops up:

EXT4-fs-error ext4_journal_start_sb.327: Detected aborted journal
...Remounting filesystem read-only

When this happens the pi also completly freezes (cant shutdown via ssh or through a plugged in keyboard).

Os: Raspbian with a kernel from the 31st August

I have tried 3 different phone chargers:

Nokia (750 ma out)
Sony ericsson (700 ma out)
Apple (1A out)

The sony ericsson one has worked the best but I cannot use the usb key.


Previously I had the pi booting from the usb key (changed /dev/mmc..0 to /dev/sda1) and this worked successfully.

Have also tried using a powered usb hub.

Thanks for your help.

Please take a look at the 'elephant in the room' thread - I think you may be seeing USB issues which this thread should be able to improve upon.

James

usb keys use a lot of current.
So the current provided by the Pi usb ports isn't enough for an usb memory stick.
Even if you have a Pi with the usb polyfuses removed, you still have the main polyfuse that will be pushed to it's limit (1.2Amps) So, your best option is a self powered hub. Polyfuses can take hours to recover, so maybe that's why it didn't work with the hub either. And yes, an rpi-update and enabling the usb patches is strongly recommended.

Thanks for the input, ill give the suggestions a go later.

Does the pi really not provide enough power for usb keys? I have not been able to find anywhere stating how much the key will use. Ive looked at plenty of tutorials etc of people using usb keys to boot from and never heard anything about an issue there.