The /etc/multipath.conf file is the standard configuration file for the Device Mapper Multipath (DM-Multipath) service on modern Linux distributions. This service is responsible for managing multiple I/O paths to storage devices, including those connected via Fibre Channel (FC). Administrators edit this file to define multipath device settings, path grouping policies, and device-specific configurations, such as those recommended by NetApp for optimal performance and failover with ONTAP LUNs. The multipathd daemon reads this file upon startup to apply the specified configuration.

A. /etc/kernel/mp.conf: This is not a standard path or filename for multipath configuration. Kernel-level parameters are typically managed through sysctl or module files in /etc/modprobe.d.

B. /opt/multipath/multipath.cnf: The /opt directory is generally used for optional, third-party software packages, not for core system services like DM-Multipath.

D. /etc/dm-multipath.conf: Although the technology is called Device Mapper Multipath (DM-Multipath), the conventional name for its configuration file is multipath.conf, not dm-multipath.conf.

1. NetApp

Inc. (2023). Linux Unified Host Utilities 7.3 Installation and Setup Guide. NetApp Documentation. In the section "Setting up the multipath.conf file

" the guide explicitly states

"You must have a properly configured /etc/multipath.conf file on your host." (See Chapter 3: SAN Administration).

2. Red Hat

Inc. (2023). Configuring device mapper multipath on RHEL 8. Red Hat Customer Portal. Chapter 3

"The multipath configuration file

" states

"The multipath configuration file is /etc/multipath.conf."

3. NetApp

Inc. (2022). TR-4080: Linux Host Configuration for ONTAP. NetApp Technical Report. Section 4.1

"Device Mapper Multipath

" details the configuration process which centers on modifying the /etc/multipath.conf file with NetApp-specific stanzas.