Updated: Wed Jul 1 21:47:50 2001  Linux Step By Steps



Understanding the topology and where Linux drivers fit in

There are two storage classes.

Block storage devices, are, to all intents the very same as your normal hard disk. They can be viewed, copied, manipulated, using the same tools and browsers such as KFM Gnome or Netscape. Block devices are Jaz, Zip, LS120. Even when connected to the parallel port. In every case the device emulates scsi. Often, the driver is multi purpose handling parallel and ide and mutliple device types (ide-floppy eg).

Streaming storage is tape. It cannot be manipulated in the same manner, it cannot be installed as a mountable device. It requires special tools for use, such as tar, mt, cpio, and archive utilities like Bru. Such devices are QIC 80 DAT, DLT tape drives, even when connected to the parallel port.

The following table illustrates the drivers (modprobe) for each block device, their heirarchy, and their relationship to each other


High Generic Interface
SCSI TAPE st scsi_mod NCR83C8xx
SCSI CD sr_mod scsi_mod NCR83C8xx
SCSI DISK sd_mod scsi_mod NCR83C8xx
SCSI ZIP sd_mod scsi_mod NCR83C8xx
SCSI JAZ sd_mod scsi_mod NCR83C8xx
SCSI LS120 sd_mod scsi_mod NCR83C8xx
IIel ZIP scsi_mod ppa/imm
IIel JAZ scsi_mod ppa/imm
IIel LS120 scsi_mod ppa/imm
IDE ZIP ide ide-floppy
IDE JAZ ide ide-floppy
IDE LS120 ide ide-floppy

*ide is normally compiled in the kernel, not a module
*NCR83C8xx is an _example_ of a specific scsi card driver.
*ppp/imm refers to old / new drive types respectively

Note some interesting results from this table. ZIP / JAZ and LS120 are all handled by the same driver in their respective interfaces. If it looks like a duck, quacks like a duck, walks like a duck, it probably is, a duck.

ALL scsi (bulk storage) devices are handled by the scsi DISK module. If it looks like a duck, quacks like a duck, walks like a duck, it probably is, a duck.


QIC/DITTO IIel zftape ftape ftape-internal
QIC/DITTO IDE zftape ftape bpck-fdc
QIC/DITTO SCSI zftape ftape ftape-scsi