FlashGrid Cluster deployed with Oracle Linux 8 will have only Red Hat kernel installed. This article provides instructions for switching to UEKR6 kernel after a cluster is deployed.
Note: The procedure can be performed on one node at a time.
To switch the RH kernel to UEKR6, repeat the following steps on each node:
a) edit /etc/dnf/dnf.conf file and comment out or remove the following line:
exclude=kernel-uek*
b) install both kernel-uek and kernel-uek-devel packages
yum install kernel-uek kernel-uek-devel
c) get info on all kernels installed
grubby --info=ALL | grep -B1 '^kernel='
(example output):
[root@rac1 ~]# grubby --info=ALL | grep -B1 '^kernel='
index=0
kernel="/boot/vmlinuz-5.4.17-2102.204.4.4.el8uek.x86_64"
--
index=1
kernel="/boot/vmlinuz-4.18.0-305.12.1.el8_4.x86_64"
--
index=2
kernel="/boot/vmlinuz-4.18.0-240.22.1.el8_3.x86_64"
d) check the default kernel
grubby --default-kernel
(example output):
[root@rac1 ~]# grubby --default-kernel
/boot/vmlinuz-5.4.17-2102.204.4.4.el8uek.x86_64
or
grubby --default-index
(example output):
[root@rac1 ~]# grubby --default-index
0
e) in case the UEKR6 kernel is not default, it needs to be set
grubby --set-default-index=<n>
where <n> is the corresponding index for UEKR6 kernel from step c) output
f) confirm the default kernel to make sure that it has been changed properly
grubby --default-kernel
h) Before repeating the steps on the next node, wait until the node boots up, all disks are back online, and resyncing operations complete on all disk groups. All disk groups must have zero offline disks and Resync = No before it is safe to update the next node. Check the status using the following command:
flashgrid-cluster
Note:
In case the scope of switching the kernel to UEKR6 is to use with ACFS/ADVM, the steps specified in How To Install/Reinstall Or Deinstall ACFS Modules/Installation Manually? (Doc ID 1371067.1) must be followed.
References:
Oracle Linux: How to Change Default Kernel on GRUB2 Using the grubby Tool (Doc ID 2605359.1)
ACFS Support On OS Platforms (Certification Matrix) (Doc ID 1369107.1)
How To Install/Reinstall Or Deinstall ACFS Modules/Installation Manually? (Doc ID 1371067.1)