HP StorageWorks Secure Path V3.0C for Linux and Linux Workgroup Edition Installation and Reference Guide (AA-RU7VD-TE, February 2004)

Secure Path Technology
18 Secure Path v3.0C for Linux and Linux Workgroup Edition Installation and Reference Guide
For HSG80, EVA5000, and EVA3000 storage systems, Secure Path enables dual
StorageWorks RAID controllers to operate in an active/active LUN ownership
implementation, referred to as dual-redundant multiple-bus mode. Multiple-bus
mode allows each controller to process I/O independently of the other controller
under normal operation. A path consists of a unique connection from adapter to
device. I/O is active on one controller at a time, and storage units (LUNs) may be
moved between paths and controllers using the Secure Path Management Tool
spmgr.
For MSA1000 storage systems, dual StorageWorks RAID controllers operate in
an Asychronous LUN presentation implementation, where one MSA1000
controller actively processes I/O and an alternate controller remains on standby.
Secure Path takes advantage of the Preferred Path attribute. For the
HSG80/HSV110/HSV100 available storage units, a path may be preferred for
each controller by setting the Preferred Path attribute.
For the MSA1000, storage units are available to the active controller. The
MSA1000 has a default preferred controller, which is used for access at storage
system boot time. During runtime, storage units may be moved between paths at
any time through the use of the Secure Path Management utility. On
HSG80/HSV110/HSV100 RAID storage systems, storage units may also be
accessed on each controller through either of two available ports.
The Secure Path software detects the failure of I/O operations on a failed path and
automatically reroutes traffic to other available paths. Secure Path software will
seek alternate paths through available SAN switches, controllers, controller ports,
and host bus adapters. Path failover is completed seamlessly, without process
disruption or data loss.
Following warm swap or replacement of a failed adapter, cable, controller, or
attached components, storage units can be restored to their original path using the
Secure Path Management utility.
To protect against drive failure in a Secure Path environment, storage units can be
configured using configuration tools. Fault tolerance is the ability to recover from
hardware problems without interrupting the server’s performance.
High availability configurations for HSG80, HSV110, and HSV100 include
RAID levels 0+1, 1, or 5.
MSA1000 High availability configurations include RAID levels 0+1, 4, or 5.