Blacklisting By Device Type; Blacklist Exceptions - Red Hat ENTERPRISE LINUX 5 DM MULTIPATH Configuration And Administration Manual

The following example shows the lines in the configuration file that would blacklist all SCSI devices,
since it blacklists are sd* devices.
blacklist {
devnode "^sd[a-z]"
}
You can use a devnode entry in the blacklist section of the configuraion file to specify individual
devices to blacklist rather than all devices of specific type; this is not recommended, however. Unless
it is statically mapped by udev rules, there is no guarantee that a specific device will have the same
name on reboot. For example, a device name could change from /dev/sda to /dev/sdb on reboot.
By default, the following devnode entries are compiled in the default blacklist; the devices that these
entires blacklist do not generally support DM-Multipath. To enable multipathing on any of these
devices, you would need to specify them in the blacklist_exceptions section of the configuration
Section 4.2.4, "Blacklist
file, as described in
blacklist {
devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
devnode "^hd[a-z]"
}

4.2.3. Blacklisting By Device Type

You can specify specific device types in the blacklist section of the configuration file with a device
section. The following example blacklists all IBM DS4200 device and all HP devices.
blacklist {
device {
vendor
product "3S42"
}
device {
vendor
product "*"
}
}

4.2.4. Blacklist Exceptions

You can use the blacklist_exceptions section of the configuration file to enable multipathing on
devices that have been blacklisted by default. For example, by default, devices with vendor = "IBM"
and product = "S/390.*" are blacklisted since usually DASD devices are used for local storage. If you
do need to enable multipathing on these devices, uncomment the following lines in the configuration
file:
Exceptions".
"IBM"
#DS4200 Product 10
"HP"
Blacklisting By Device Type
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