Red Hat Enterprise Linux 5DM MultipathDM Multipath Configuration and Administration

Chapter 1. Device Mapper Multipathing2Figure 1.1. Active/Passive Multipath Configuration with One RAID DeviceIn this configuration, there is one I/O p

Overview of DM-Multipath3Figure 1.2. Active/Passive Multipath Configuration with Two RAID DevicesIn the example shown in Figure 1.2, “Active/Passive M

Chapter 1. Device Mapper Multipathing4Figure 1.3. Active/Active Multipath Configuration with One RAID Device1.3. Storage Array SupportBy default, DM-M

DM-Multipath Setup Overview51.5. DM-Multipath Setup OverviewDM-Multipath includes compiled-in default settings that are suitable for common multipathc

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Chapter 2.7Multipath DevicesWithout DM-Multipath, each path from a server node to a storage controller is treated by the systemas a separate device, e

Chapter 2. Multipath Devices8If you want the system-defined user-friendly names to be consistent across all nodes in the cluster,however, you can foll

Multipath Device Attributes92.3. Multipath Device AttributesIn addition to the user_friendly_names and alias options, a multipath device has numerousa

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Chapter 3.11Setting Up DM-MultipathThis chapter provides step-by-step example procedures for configuring DM-Multipath. It includes thefollowing proced

DM MultipathRed Hat Enterprise Linux 5 DM MultipathDM Multipath Configuration and AdministrationEdition 3Copyright © 2011 Red Hat, Inc.The text of and

Chapter 3. Setting Up DM-Multipath12The multipath -v2 command prints out multipathed paths that show which devices aremultipathed. If the command does

Ignoring Local Disks when Generating Multipath Devices13create: 3600a0b80001327510000009b4362163e[size=12 GB][features="0"][hwhandler="

Chapter 3. Setting Up DM-Multipath14create: 3600a0b80001327510000009b4362163e[size=12 GB][features="0"][hwhandler="0"]\_ round-rob

Chapter 4.15The DM-Multipath Configuration FileBy default, DM-Multipath provides configuration values for the most common uses of multipathing.In addi

Chapter 4. The DM-Multipath Configuration File16When the system determines the attributes of a multipath device, first it checks the multipath setting

Blacklisting By Device Type17}You can use a devnode entry in the blacklist section of the configuration file to specify individualdevices to blacklist

Chapter 4. The DM-Multipath Configuration File184.3. Configuration File DefaultsThe /etc/multipath.conf configuration file includes a defaults section

Configuration File Defaults19Attribute Descriptionpolling_interval Specifies the interval between two path checks in seconds. Thedefault value is 5.se

Chapter 4. The DM-Multipath Configuration File20Attribute DescriptionA value of 0 or immediate specifies that as soon as there is apath group with a h

Multipaths Device Configuration Attributes21Attribute Descriptionthe sum of the priorities of the included paths. The default value issum.log_checker_

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Chapter 4. The DM-Multipath Configuration File22Attribute DescriptionA value of 0 or immediate specifies that as soon as there is apath group with a h

Configuration File Devices23 rr_weight priorities no_path_retry 5 } multipath {

Chapter 4. The DM-Multipath Configuration File24Attribute Descriptionproduct Specifies the product name of the storage device to which thedevice attri

Configuration File Devices25Attribute DescriptionA numeric value greater than zero specifies deferred failback,expressed in seconds.A value of manual

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Chapter 5.27DM-Multipath Administration andTroubleshootingThis chapter will provide information on administering DM-Multipath on a running system. It

Chapter 5. DM-Multipath Administration and Troubleshooting285.2. The Multipath DaemonIf you find you have trouble implementing a multipath configurati

Multipath Queries with multipath Command29For each multipath device: action_if_any: alias (wwid_if_different_from_alias) [size][features][hardware_han

Chapter 5. DM-Multipath Administration and Troubleshooting30mpath1 (3600d0230003228bc000339414edb8101)[size=10 GB][features="0"][hwhandler=&

Troubleshooting with the multipathd Interactive Console31help to get a list of available commands, you can enter a interactive command, or you can ent

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33Appendix A. Revision HistoryRevision 5.7-1 Thu Jul 21 2011 Steven Levine [email protected]: #703610Documents new configuration file paramet

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35IndexSymbols/etc/multipath.conf package, 11Aactive/active configurationdefinition, 1illustration, 3active/passive configurationdefinition, 1illustra

Index36feedback, v, vfile_timeout parameter, 18flush_on_last_del parameter, 18, 21, 23Ggetuid_callout parameter, 18, 23gid parameter, 18, 21Hhardware_

vPrefaceThis book describes the Device Mapper Multipath (DM-Multipath) feature of Red Hat Enterprise Linuxfor the Red Hat Enterprise Linux 5 release.1

PrefaceviBe sure to mention the manual's identifier:Bugzilla component: Documentation-clusterBook identifier: DM_Multipath(EN)-5 (2011-07-2115:35

Pull-quote ConventionsviiFile-related classes include filesystem for file systems, file for files, and dir fordirectories. Each class has its own asso

Prefaceviiibooks Desktop documentation drafts mss photos stuff svnbooks_tests Desktop1 downloads images notes scripts svgsS

Chapter 1.1Device Mapper MultipathingDevice Mapper Multipathing (DM-Multipath) allows you to configure multiple I/O paths between servernodes and stor