Some USB storage devices work, others don't

[ChrisA]

I'm an experianced *nix user, admin and programmer but I think I must have been living in a cave the last few years as I'm just now getting around to playing with USB storage. My problem is that I don't know how it works so I can't debug it. Pointers to info and/or hints would be nice.

Here is what's happing on my Fodora 3 machine:

I made a mont point in /etc/fstab called /mnt/usb. I can plug in my little 32MB USB drive and mount it. It works fine. It shows up with "lsusb" I can read/write file. All is well. My Sony camcorder (TRV33) has a sony memory stick inside. When I plug the camcorder into USB it works fine also. So there is good proof the drivers, generic SCSI and so on are all there.

Problem: Some devices simply "don't work". They don't even show up with "lsusb". These devices work under Windows 2000 and XP. The devices that fail are generic multi-card readers. I'd ike to install a card reader in an external drive bay but so far no luck with these.

I'm sure if the device will show up with lsusb I can make it go from there. But I do't uderstand what chain of events has to happen to cause a device o appear with lsusb.

So far the only documentation for debugging USB storage starts with "step one, Look at the output of lsusb." What's step zero?

Thanks,

[Mord]

In direct response to your question, Step 0 is watching dmesg and/or /var/log/messages to see if there are any entries corresponding to the connection/detection of the USB card reader device, either on boot, when its connected, and/or when you insert some type of media into the reader.

I pulled up this link for card readers under linux (there's plenty of info around, and don't worry, there's plenty of people having trouble with these bloody things):

http://www.linux-sxs.org/hardware/flashreaders.html

(There seems to be a tendency for people to compile the usb support as kernel modules rather than right into the kernel. I've had success either way.)

[mcewena1]

I don't know if you already found this but I found it today. I haven't had time to read it let alone understand it but it looks pretty complete at first glance

[mcewena1]

http://www.linux-usb.org/

Sorry. somehow I forgot to paste the above link in the above message