Ignoring Local Disks When Generating Multipath Devices - Red Hat DEVICE-MAPPER MULTIPATH 4.6 Configuration And Administration Manual

Chapter 3. Setting Up DM-Multipath
3. Save the configuration file and exit the editor.
4. Execute the following commands:
modprobe dm-multipath
service multipathd start
multipath -v2
The
multipath -v2
multipathed. If the command does not print anything out, ensure that all SAN connections are
set up properly and the system is multipathed.
For further information on the
Command Output".
5. Execute the following command to ensure sure that the multipath daemon starts on bootup:
chkconfig multipathd on
Since the value of
user_friendly_name
devices will be created as
device to an alias of your choosing, see
2. Ignoring Local Disks when Generating Multipath
Devices
Some machines have local SCSI cards for their internal disks. DM-Multipath is not
recommended for these devices. The following procedure shows how to modify the multipath
configuration file to ignore the local disks when configuring multipath.
1. Determine which disks are the internal disks and mark them as the ones to blacklist.
In this example,
/dev/sda
multipath configuration file, executing the
the multipath map.
For further information on the
Command Output".
[root@rh4cluster1 ~]# multipath -v2
create: SIBM-ESXSST336732LC____F3ET0EP0Q000072428BX1
[size=33 GB][features="0"][hwhandler="0"]
\_ round-robin 0
\_ 0:0:0:0 sda
12
command prints out multipathed paths that show which devices are
command output, see
multipath
is set to
/dev/mapper/mpathn
Chapter 4, The DM-Multipath Configuration
is the internal disk. Note that as originally configured in the default
multipath -v2
command output, see
multipath
8:0 [---------
Section 1, "Multipath
in the configuration filea the multipath
yes
. For information on setting the name of the
shows the local disk,
Section 1, "Multipath
File.
, in
/dev/sda