Chapter 4. The DM-Multipath Configuration File
12
devices
Settings for the individual storage controllers. These values overwrite what is specified in the
defaults
section of the configuration file. If you are using a storage array that is not supported
by default, you may need to create a
devices
subsection for your array.
When the system determines the attributes of a multipath device, first it checks the multipath settings,
then the per devices settings, then the multipath system defaults.
4.2. Configuration File Blacklist
The
blacklist
section of the multipath configuration file specifies the devices that will not be used
when the system configures multipath devices. Devices that are blacklisted will not be grouped into a
multipath device.
By default, all devices are blacklisted, since the following lines appear in the initial configuration file.
blacklist {
devnode "*"
}
To enable multipathing on all of the devices that are supported by default, comment out those lines, as
described in
Section 3.1, “Setting Up DM-Multipath”
.
After commenting out the universal blacklist, you can specify general device types and individual
devices to blacklist. You can blacklist devices according to the following criteria:
• By WWID, as described in
Section 4.2.1, “Blacklisting by WWID”
• By device name, as described in
Section 4.2.2, “Blacklisting By Device Name”
• By device type, as described in
Section 4.2.3, “Blacklisting By Device Type”
By default, a variety of device types are blacklisted, even after you comment out the initial blacklist
section of the configuration file. For information, see
Section 4.2.2, “Blacklisting By Device Name”
.
4.2.1. Blacklisting by WWID
You can specify individual devices to blacklist by their World-Wide IDentification with a
wwid
entry in
the
blacklist
section of the configuration file.
The following example shows the lines in the configuration file that would blacklist a device with a
WWID of 26353900f02796769.
blacklist {
wwid 26353900f02796769
}
4.2.2. Blacklisting By Device Name
You can blacklist device types by device name so that they will not be grouped into a multipath device
by specifying a
devnode
entry in the
blacklist
section of the configuraion file.
