USB Flash Reader on Linux Fedora Core 1

With digital cameras so popular, the USB multi-format card readers are readily available, inexpensive, and supported on Linux.

The memory cards in the reader show up as SCSI disk devices. The digital camera manufacturers have standardized on the MSDOS FAT filesystem, so you can just read and write to the memory card through the reader as if it were a disk drive.

Many USB card readers show up in Linux as a multi-LUN SCSI device. This means that only the first slot is seen by default. You may see the compact-flash slot but not the SmartMedia or MMC slot. To fix this, your Linux kernel needs to scan for the extra LUNs.

For Fedora Core 1, I added the following line to /etc/modules.conf:

   options scsi_mod max_scsi_luns=6 

as mentioned on the Fedora mailing list. More information is on the Linux flash readers page, or using a USB card reader in Linux.

You can also recompile your kernel with the option "CONFIG_SCSI_MULTI_LUN=y" enabled, or you can add a "max_scsi_luns=6" option at boot time in Grub.