Supports the serial DASD physical volume (fixed-disk) subsystem device driver.
#include <sys/devinfo.h> #include <sys/scsi.h> #include <sys/serdasd.h>
The serial DASD Subsystem is a serial-link disk subsystem, consisting of the following components:
Note: The serial DASD subsystem adapters are not SCSI adapters, and the subsystem is not a SCSI Bus. The controllers and DASD subsystem use the SCSI protocol for command packaging. They are not SCSI devices.
Attention: Potential for data corruption or system crashes: Data corruption, loss of data or loss of system integrity occurs if devices supporting paging, logical volumes, or mounted file systems are accessed using block special files. Block special files are provided for logical volumes and disk devices and are solely for system use in managing file systems, paging devices, and logical volumes. Direct access to physical disks through /dev/hdiskn block special files could cause the system to experience performance difficulties. These difficulties include data consistency problems between data in the block I/O buffer cache and data in system pages.
Note: The maximum transfer request through the /dev/hdiskn block special file is 128K bytes.
The /dev/rhdisk special file provides raw I/O access and control functions to the physical disk device drivers. Raw I/O access is provided through the /dev/rhdisk0, /dev/rhdisk1, and other character special files.
The prefix of r on a special file name indicates that the drive is accessed as a raw device rather than a block device. Performing raw I/O with a fixed disk requires that all data transfers be in multiples of the disk block size. Also, all lseek subroutines that are made to the raw-disk device driver must result in a file pointer value that is a multiple of the disk block size.
The /dev/serdasdcn special file provides access and control functions to the Serial DASD Subsystem controllers. Access to the controllers, primarily for diagnostic purposes, is through the /dev/serdasdc0, /dev/serdasdc1, and other special files.
The /dev/serdasdan special file provides access and control functions to the Serial DASD Subsystem adapters. Access to the adapters, primarily for diagnostic purposes, is through the /dev/serdasda0, /dev/serdasda1, and other special files.
There is also a /dev/dserdasdan adapter special file for each adapter reserved for use by the RAS configuration daemon.
Device-Dependent Subroutines for the Serial DASD Subsystem.
Error Conditions for Serial DASD Subroutines .
Reliability, Availability, and Serviceability (RAS) Daemon for the Serial DASD Subsystem .
The /dev/rhdisk special file, /dev/serdasda special file, /dev/serdasdc special file.
The lseek subroutine.