To provide a redundant path to the storage array, you can configure the host to run failover.
What you’ll need
You must install 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
Refer to Lenovo Storage Interoperation Center (LSIC) to ensure any required updates are installed as multipathing may not work correctly with the GA versions of SLES or RHEL.
About this task
RHEL 7 and SLES 12 use Device Mapper Multipath (DMMP) for multipathing when using NVMe over Infiniband. RHEL 8, RHEL9, and SLES 15 use a built in Native NVMe Failover. Depending on which OS you are running, some additional configuration of multipath is required to get it running properly.
Enable Device Mapper Multipath (DMMP) for RHEL 7 or SLES 12
By default, DM-MP is disabled in RHEL and SLES. Complete the following steps to enable DM-MP components on the host.
Steps
-
Add the NVMe DE-Series device entry to the devices section of the /etc/multipath.conf file, as shown in the following example:
devices { device { vendor "NVME" product "Lenovo DE_Series *" path_grouping_policy group_by_prio failback immediate no_path_retry 30 } }
-
Configure
multipathd
to start at system boot.# systemctl enable multipathd
-
Start
multipathd
if it is not currently running.# systemctl start multipathd
-
Verify the status of
multipathd
to make sure it is active and running:# systemctl status multipathd
== Setting up RHEL 8 with Native NVMe Multipathing
Native NVMe Multipathing is disabled by default in RHEL 8 and must be enabled using the steps below.
-
Setup
modprobe
rule to turn on Native NVMe Multipathing.# echo "options nvme_core multipath=y" >> /etc/modprobe.d/50-nvme_core.conf
-
Remake
initramfs
with newmodprobe
parameter.# dracut -f
-
Reboot server to bring it up with the Native NVMe Multipathing enabled.
# reboot
-
Verify Native NVMe Multipathing has been enabled after the host boots back up.
# cat /sys/module/nvme_core/parameters/multipath
-
If the command output is
N
, then Native NVMe Multipathing is still disabled. -
If the command output is
Y
, then Native NVMe Multipathing is enabled and any NVMe devices you discover will use it.
-
For SLES 15 and RHEL9, Native NVMe Multipathing is enabled by default and no additional configuration is required. |