Installing DM-MP

All of the components required for DM-MP are included on the installation media.

Before you begin

You have installed the required packages on your system.

For Red Hat (RHEL) hosts, verify the packages are installed by running rpm -q device-mapper-multipath.
For SLES hosts, verify the packages are installed by running rpm -q multipath-tools.

By default, DM-MP is disabled in RHEL and SLES. Complete the following steps to enable DM-MP components on the host.

If you have not already installed the operating system, use the media supplied by your operating system vendor.

Use the procedures in the Setting up the multipath.conf file to update and configure the /etc/multipath.conf file.

Do one of the following to enable the multipathd daemon on boot.

If you are using....	Do this ...
For RHEL 6.x systems:	chkconfig multipathd on
For SLES 11.x systems:	chkconfig multipathd on chkconfig boot.multipath on
For RHEL 7.x and SLES 12.x systems:	systemctl enable multipathd

Rebuild the initramfs image or the initrd image under /boot directory:

If you are using....	Do this ...
For SLES 11.x systems:	mkinitrd -k /boot/vmlinux-<flavour> -i /boot/initrd-<flavour>.img -M /boot/System.map-<flavour> In this command, <flavour> is replaced with running kernel version from command "uname -r".
For RHEL 6.x 7.x and 12.x systems:	dracut --force --add multipath

Make sure that the newly created /boot/initrams-* image or /boot/initrd-* image is selected in the boot configuration file.
For example, for grub it is /boot/grub/menu.lst and for grub2 it is /boot/grub2/menu.cfg.
Do one of the following to verify and, if necessary, change the host type.
- If you have hosts defined in the SANtricity Storage Manager Host Mappings View, go to step 6.
- If you do not have hosts defined, right-click the default host group in the SANtricity Storage Manager Host Mappings View, and then set the default host type to either Linux DM-MP (Kernel 3.10 or later) if you enable the Automatic Load Balancing feature, or Linux DM-MP (Kernel 3.9 or earlier) if you disable the Automatic Load Balancing feature. . Go to step 7.
- If you are using SANtricity System Manager, use the "Create host manually" procedure in the online help to check the whether the hosts are defined and update as necessary in step 7.
In the SANtricity Storage Manager mappings view, right-click the host, and then select Change Host Operating System.
Verify that the selected host type is either Linux DM-MP (Kernel 3.10 or later) if you enable the Automatic Load Balancing feature, or Linux DM-MP (Kernel 3.9 or earlier) if you disable the Automatic Load Balancing feature. If necessary, change the selected host type to the appropriate setting.
Reboot the host.