Using Device-Mapper Multipath

Using Device-Mapper Multipath

Configuration and Administration

Legal Notice

May 2008


This book provides information on using the Device-Mapper Multipath feature of Red Hat Enterprise Linux 5.2

1. Audience
2. Related Documentation
3. Feedback
4. Document Conventions
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. Multipath Command Output
5.2. Multipath Queries with multipath Command
5.3. Multipath Command Options
5.4. Determining Device Mapper Entries with the dmsetup Command
5.5. Troubleshooting with the multipathd Interactive Console

Note: This documentation is provided {and copyrighted} by Red Hat®, Inc. and is released via the Open Publication License. The copyright holder has added the further requirement that Distribution of substantively modified versions of this document is prohibited without the explicit permission of the copyright holder. The CentOS project redistributes these original works (in their unmodified form) as a reference for CentOS-5 because CentOS-5 is built from publicly available, open source SRPMS. The documentation is unmodified to be compliant with upstream distribution policy. Neither CentOS-5 nor the CentOS Project are in any way affiliated with or sponsored by Red Hat®, Inc.