USB

Since the 2.6 series of Linux kernels, USB devices have been handled by DBus and HAL. This means that automatically mounting peripherals like digital cameras, flash drives (thumb drives), card readers or USB hubs is handled automatically in 'user' space (avoiding problems with permissions).

I bought a digital photo frame (Coby), which can use multiple memory sources (Memory Stick (MS), Compact Flash (CF), Secure Digital (SD), etc.). Since 2 Gigabyte SD cards can be bought for ~$20 these days, I figured I would buy a couple of those and fill them with images for the photo frame. In order to get photos from my computer onto the SD cards, I bought a multi-card reader. To upgrade my computer from USB 1.1 to USB 2, I threw in a USB 2 PCI card. To make it more convenient to use the PCI card ports, I bought a USB 2 hub, plus three 6' extension cables. All this great new USB gear was bound to make my digital life easier to manage.

Multi Card Reader

http://www.syba.com/Product/Info/Id/125 It would appear that the multi-card reader does not support SD with capacity over 1GB. In order to test whether the card reader was working at all, I used some older, smaller 8MB and 32MB CF cards. Using only one of those cards, the reader worked without problem. If a 2GB SD card was inserted, then the reader would not work at all, causing WinXP to nearly halt. In Debian or Kubuntu linux, the card reader would appear to the operating system, but it would not automatically mount the card because obviously the card reader was not presenting a filesystem to mount.

Unfortunately, it took me a long time to figure out how these systems work, and the tools an 'advanced' computer user can use to diagnose things when they don't happen automatically.

The word SCSI (OK, that's not a word, but say 'scuzzy') always confused me. I always associated it with the type of disk drive and drive controller you might find in a computer (more advanced, and more expensive compared with IDE, ATA, SATA). The part that confused me was that so many things in Linux operate under SCSI emulation (CD-ROM drives and USB devices for example). Well, this chart helps to make it clear that SCSI applies to many things besides a hard drive. When you see 'SCSI emulation' or drivers supporting devices in Linux refering to the SCSI command protocol (one part of SCSI), and not the physical interface. http://web.it.kth.se/~f/cardreaderhowto/whyoptions.html

Finding the drive <bash> ls -l /dev/disk/by-id/usb* </bash>

• lsmod
• lshal

More resources:

• http://gentoo-wiki.com/HOWTO_USB_Mass_Storage_Device