Users Guide

chkcong boot.multipath on

If the boot.multipath service does not start automatically on system boot, do the following to start them manually:

/etc/init.d/boot.multipath start

/etc/init.d/multipathd start

3 Multipath conguration can be veried with the information in /etc/multipath.conf le by utilizing following commands.

multipath -v2 –d

multipath -v3 –d

Once the above commands are veried to be successful, the multipath devices are available at /dev/mapper/mpathX by default

where X is multipath eligible devices.

You can use multipath-ll to verify the status of the multipath conguration. The output should be similar to the details shown below:

linux-ha-2:~ #multipath –ll

mpathc (3690b11c025a5ef001b289a2f60d160b6) dm-1 DELL, Shared PERC8

size=50G features='0' hwhandler='0' wp=rw

|-+- policy='round-robin 0' prio=50 status=active

| `- 1:2:1:0 sdc 8:32 active ready running

`-+- policy='round-robin 0' prio=10 status=enabled

`- 2:2:1:0 sde 8:64 active ready running

mpathb (3690b11c025a5ef001b2895c11d374ab5) dm-0 DELL, Shared PERC8

size=10G features='0' hwhandler='0' wp=rw

|-+- policy='round-robin 0' prio=50 status=active

| `- 1:2:0:0 sdb 8:16 active ready running

`-+- policy='round-robin 0' prio=10 status=enabled

`- 2:2:0:0 sdd 8:48 active ready running

In the above output, the status eld shows us whether a path is active or enabled. The active path services the IO. Priority eld is

also used with status eld to identify the path to be used with highest priority. Also each path has a unique access identier to the

shared VD (For mpathc it is /dev/sdc and /dev/sde)

Multipath conguration in RHEL

1 Modify the multipath.conf le at /etc/multipath.conf with the parameters as suggested inMultipath les for Linux multipath

conguration. If copying the le from Windows, please use dos2unix multipath.conf le once you have copied it over.

2 To start multipath services and enable them to start at reboot:

chkcong multipathd on

If the boot.multipath service does not start automatically on system boot, do the following to start them manually:

/etc/init.d/multipathd start

Multipath and clustering setup