Secure Path v2.0 for Sun Solaris Installation and Reference Guide

Technical Description 2-3

Compaq Confidential – Need to Know Required

Writer: Cyndi Vaccaro Project: StorageWorks Secure Path Version 2.0 for Sun Solaris Comments:

Part Number: AA-RKYDA-TE File Name: c-ch2 Technical Description.doc Last Saved On: 12/21/99 4:52 PM

Secure Path Drivers

Secure Path consists of three drivers that together create and manage paths to a

storage device while providing a single device target to applications. Figure 2-

2 illustrates the driver model structure.

ldLite

mda

Fibre Channel

driver

Path

SHR-1607

Figure 2-2. StorageWorks Secure Path V2.0 Driver Model

■ mda

The mda driver is a SCSI-disk target driver specific to the Compaq HSG80

fibre attached RAID storage system controller. The mda driver is a path

failover driver which provides I/O paths to the storage devices. It also

monitors the paths and, when a path failure is detected, automatically

initiates path failover.

■ ldLite

The ldLite driver is a pseudo-HBA driver that presents separate mda

instances as a single device to the Solaris sd driver.

■ path

The path driver provides facilities for the ldLite and mda drivers to

communicate in the kernel. It also provides a character device interface that

is used by the Secure Path management utility to manage the state of the

paths to each storage device. The path driver is not used for any device I/O.

Failover

Secure Path redirects I/O from a failed physical path to the path still

functioning. This process is known as path failover. If a problem with a host