Red Hat ENTERPRISE LINUX 5.1 DM MULTIPATH Configuration And Administration Manual

Blacklisting By Device Type13The 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 individualdevices to blacklist rather than all devices of specific type; this is not recommended, however. Unlessit is statically mapped by udev rules, there is no guarantee that a specific device will have the samename 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 theseentires blacklist do not generally support DM-Multipath. To enable multipathing on any of thesedevices, you would need to specify them in the blacklist_exceptions section of the configurationfile, as described in Section 4.2.4, “Blacklist Exceptions”.blacklist {devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"devnode "^hd[a-z]"}4.2.3. Blacklisting By Device TypeYou can specify specific device types in the blacklist section of the configuration file with a devicesection. The following example blacklists all IBM DS4200 device and all HP devices.blacklist {device {vendor "IBM"product "3S42" #DS4200 Product 10}device {vendor "HP"product "*"}}4.2.4. Blacklist ExceptionsYou can use the blacklist_exceptions section of the configuration file to enable multipathing ondevices 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 youdo need to enable multipathing on these devices, uncomment the following lines in the configurationfile: