Red Hat GNBD WITH GLOBAL FILE SYSTEM IN RHEL 4.5 Installationsanleitung PDF herunterladen (Seite 24)

Chapter 4. The DM-Multipath Configuration File

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 configuration file.

The following example shows the lines in the configuration file that would blacklist all SCSI devices,

since it blacklists all sd* devices.

blacklist {

devnode "^sd[a-z]"

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Red Hat GNBD WITH GLOBAL FILE SYSTEM IN RHEL 4.5 Installationsanleitung Seite 24