HP StorageWorks MultiPulse failover driver for Linux application notes Part number: AA-RWENC-TE Second edition: January 2007
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About this document This document describes how to install and configure the Emulex MultiPulse driver for Linux® (MultiPulse). MultiPulse provides failover functionality for storage targets discovered through Emulex Fibre Channel host bus adapters (HBAs). When a path to a device fails, MultiPulse reroutes the I/O to an alternative path to that same device without disrupting service.
System requirements Table 1 lists the supported operating systems, HBAs, and storage arrays. Table 1 System requirements Feature Requirement MultiPulse driver • 2.1.9 for (RHEL) 4, Updates 3 and 4; (SLES) 9, SP3 • 2.2.12 for (SLES) 10 Emulex base driver • 8.0.16.27 for (RHEL) 4, Updates 3 and 4; (SLES) 9, SP3 • 8.1.6.
Prerequisites Before you install the MultiPulse driver, ensure that your system meets the requirements described in "System requirements" on page 4. Driver installation To install the MultiPulse driver: 1. Enter the following command to untar hp-lpfc-.tar.gz: # tar zxvf hp-lpfc-.tar.gz The is the release date of the .gz file. 2. Change to the newly created hp-lpfc- directory: # cd hp-lpfc- 3. Run the INSTALL script: # .
Driver parameters Table 2 lists the MultiPulse driver parameters. Table 2 MultiPulse driver parameters Parameter Description lpfc_nodev_tmo Time, in seconds, that the driver holds I/O for a device that is no longer accessible. The default value is 30 seconds for single-path configurations. The MultiPulse installation changes this value to 10 seconds so that path failure notification occurs more quickly. lpfc_lun_queue_depth Queue depth per LUN. The default value is 16.
Manual rescan When a server configured with MultiPulse first boots, MultiPulse automatically recognizes up to four physical paths and associates them with the same virtual device. However, after the initial configuration, MultiPulse does not recognize a new physical path that comes online to an already configured LUN. To enable MultiPulse to recognize the new physical path, you must perform a manual rescan using the hp_rescan utility. To manually rescan: 1.
