A computer uses a wide range of peripheral devices and mass-storage devices such as drives, printers, and so on. The Oracle Solaris software does not directly communicate with all of these devices. Each type of device requires different data formats, protocols, and transmission rates.
A device driver is a low-level program that enables the operating system to communicate with a specific piece of hardware. The driver serves as the operating system's "interpreter" for that piece of hardware.
You can customize a driver configuration by adding or modifying either a per-device parameter or a global property in that driver's configuration file. The addition or modification affects all devices in the system. In the Oracle Solaris 11.4 release, driver customizations are made in the /etc/driver/drv directory rather than in the /kernel directory as in previous releases. Files in the /etc/driver/drv directory are preserved during the upgrade. Thus, your driver customizations are not overwritten when the system is upgraded.
# cp /kernel/drv/sd.conf /etc/driver/drv/sd.conf
For example, the sd.conf file includes the following entry for the SCSI (pronounced "scuzzy") sd device at target 0, lun 0:
name="sd" class="scsi" target=0 lun=0;
To add the retries parameter for this device, modify the existing entry as follows:
name="sd" class="scsi" target=0 lun=0 retries=4;
For example:
# prtconf -vu sd, instance #1 Admin properties: name='retries' type=int items=1 value=00000004