Max Rible Kaehn - 2002-05-16

The section on Mass Storage Devices gives example /dev entries for mounting USB devices, such as /dev/sda1 for a hard drive or /dev/sda4 for a Zip drive, but simply states "Note that the above entries assume you have no other SCSI devices. If you do have other devices, then the USB disk may not be /dev/sda, but could instead be /dev/sdb, /dev/sdc or some other device. You would then need to substitute the right device entry for /dev/sda or /dev/scd0 in the entries above."

How do you know which /dev entry a given USB device will be occupying when you hook it up?  On Red Hat 7.2, when I plug in a SanDisk ImageMate CF card reader, "cat /proc/bus/usb/devices" tells me all the expected details, and "cat /proc/scsi/scsi" tells me it's "Host: scsi0 Channel: 00 Id: 00 Lun: 00", but I can't figure out which /dev entry it goes to.  I've tried mounting many different /dev/sda and /dev/scd entries, but I just get messages like

mount: block device /dev/sda1 is write-protected, mounting read-only

mount: /dev/sda1 is not a valid block device

To add to the confusion, Red Hat 7.2 seems to have
/dev/sda[a-z][1-15] for extra combinations.

How do I find out where this assignment takes place?  dmesg will tell me where on the USB bus the device is connected (and say "WARNING: USB Mass Storage data integrity not assured"), but no further clues.

Thanks,
Max