PC Hardware in a Nutshell, 3rd Edition

Enabling the ide-scsi driver

Although Linux recognizes the DVD-RAM drive immediately after it is installed, it does so using the standard ide driver. By default the standard ide driver takes control of all IDE devices, including ATA hard drives and ATAPI optical drives. The standard ide driver is sufficient for hard drives and for read-only optical drives, but writable optical drives require SCSI emulation. The ide-scsi driver provides that emulation.

Tip

Linux supports SCSI CD writers and DVD writers directly. The ide-scsi driver is necessary only to provide SCSI emulation to ATAPI CD/DVD writers. Some recent Linux releases recognize CD/DVD writers at install time and automatically enable ide-scsi support. If you are using an earlier release or adding an ATAPI CD or DVD writer to an existing system, you may need to enable ide-scsi support manually.

The easiest way to enable ide-scsi emulation is to add or edit a line in your boot configuration file. First, use the command grep ATAPI /var/log/dmesg to verify drive configuration. You should see output similar to that shown in Example 12-2. In this example, the DVD writer for which we want to enable SCSI emulation via the ide-scsi driver is currently recognized by the system as hdd, under the control of the standard ide driver.

Example 12-2. Using the grep command to verify drive configuration

[thompson@caldwell thompson]$ grep ATAPI /var/log/dmesg hdc: PLEXTOR CD-R PX-W2410A, ATAPI CD/DVD-ROM drive hdd: HITACHI GF-1000 B, ATAPI CD/DVD-ROM ...