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Red Hat Enterprise Linux 5

DM Multipath

DM Multipath Configuration and Administration

Edition 3

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Abstract
This book provides information on using the Device-Mapper Multipath feature of Red Hat Enterprise Linux 5
Preface
1. Audience
2. Related Documentation
3. Feedback
4. Document Conventions
4.1. Typographic Conventions
4.2. Pull-quote Conventions
4.3. Notes and Warnings
1. Device Mapper Multipathing
1.1. Overview of DM-Multipath
1.2. Storage Array Support
1.3. DM-Multipath Components
1.4. DM-Multipath Setup Overview
2. Multipath Devices
2.1. Multipath Device Identifiers
2.2. Consistent Multipath Device Names in a Cluster
2.3. Multipath Device Attributes
2.4. Multipath Devices in Logical Volumes
3. Setting Up DM-Multipath
3.1. Setting Up DM-Multipath
3.2. Ignoring Local Disks when Generating Multipath Devices
3.3. Adding Devices to the Multipathing Database
4. The DM-Multipath Configuration File
4.1. Configuration File Overview
4.2. Configuration File Blacklist
4.2.1. Blacklisting by WWID
4.2.2. Blacklisting By Device Name
4.2.3. Blacklisting By Device Type
4.2.4. Blacklist Exceptions
4.3. Configuration File Defaults
4.4. Multipaths Device Configuration Attributes
4.5. Configuration File Devices
5. DM-Multipath Administration and Troubleshooting
5.1. The Multipath Daemon
5.2. Issues with Large Number of LUNs
5.3. Issues with queue_if_no_path feature
5.4. Multipath Command Output
5.5. Multipath Queries with multipath Command
5.6. Multipath Command Options
5.7. Determining Device Mapper Entries with the dmsetup Command
5.8. Troubleshooting with the multipathd Interactive Console
A. Revision History
Index