Red Hat DEVICE-MAPPER MULTIPATH 5.2, Configuration And Administration Manual

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Component Description
multipath
command Lists and configures multipath devices. Normally started up
with
/etc/rc.sysinit
, it can also be started up by a
udev
program whenever a block device is added or it can be run by
the
initramfs
file system.
multipathd
daemon Monitors paths; as paths fail and come back, it may initiate
path group switches. Provides for interactive changes to
multipath devices. This must be restarted for any changes to
the
/etc/multipath.conf
file.
kpartx
command Creates device mapper devices for the partitions on a device
It is necessary to use this command for DOS-based partitions
with DM-MP. The
kpartx
is provided in its own package, but
the
device-mapper-multipath
package depends on it.
Table 1.1. DM-Multipath Components
4. DM-Multipath Setup Overview
DM-Multipath includes compiled-in default settings that are suitable for common multipath
configurations. Setting up DM-multipath is often a simple procedure.
The basic procedure for configuring your system with DM-Multipath is as follows:
1. Install
device-mapper-multipath
rpm.
2. Edit the
multipath.conf
configuration file:
• comment out the default blacklist
• change any of the existing defaults as needed
• save the configuration file
3. Start the multipath daemons.
4. Create the multipath device with the
multipath
command.
Detailed setup instructions for several example multipath configurations are provided in see
Chapter 3, Setting Up DM-Multipath .
DM-Multipath Setup Overview
5