NAME

dsa - low-level module for Dell SCSI Array Controller (DSA)

AVAILABILITY

x86

DESCRIPTION

The dsa module provides low-level interface routines between the common disk/tape I/O subsystem and the Dell EISA bus master controller. The dsa module can be configured for disk and raid disks on up to four host adapter boards. These disks are called composite disks in Dell configuration software. Auto configuration code determines if the adapter is present at the configured address and what devices are attached to it. Non composite drives attached to the bus of a DSA controller are accessed through Adaptec 1540 emulation. See the entry aha(7).

Board Configuration and Auto

The Dell EISA configuration utility must be run to properly initialize access to the controller. One controller should have the adapter bios enabled. If the DSA controller is used to read the Solaris CD disk for installation, Adaptec 1540A emulation should be enabled.

Configuration

All hard drives accessible by the dsa driver must be configured by the Dell Array Manager software as composite drives. All raid levels supported by Dell are visible to the dsa driver. A controller can be in slots one through eight. If the DSA controller is used for Solaris x86 CD installation, the CD must be mapped at the proper target, which cannot be 0. The DSA controller is target 0 on the SCSI bus but should be set up to appear as target 7 in the emulation mappings.

The driver attempts to initialize itself in accordance with the information found in the configuration file, /kernel/drv/dsa.conf. There are no user configurable items in this file.

The default listing of the an item in the configuration file is as follows:

name="dsa" class="sysbus" interrupts=5,11,5,12,5,13,5,14,5,15
        reg=0x1c80,0,0 ioaddr=0x1c80
        flow_control="dmult" queue="qfifo" disk="dadk" ;

The driver determines the interrupt from the board at initialization time.

To speed boot, parameters in the configuration file may be commented out with a "#" in the first column of all three lines for controllers that are not installed. The first number in the "reg" and "ioaddr" addresses indicates the EISA slot number. Hence, "2c80" indicates the I/O address of the DSA controller in EISA slot 2.

FILES

/kernel/drv/dsa.conf

configuration file for the dsa driver.

SEE ALSO

aha(7)

NOTES

Note that although the DSA controller is physically connected to SCSI devices, the interface to composite drives is that of a direct access disk "dadk." There is no way to send SCSI commands to composite drives on a DSA controller. Non composite devices (such as tape and CD) can not be accessed via the dsa driver.