커널 업그레이드

# cat /etc/redhat-release
CentOS Linux release 7.8.2003 (Core)

# uname -a
Linux dtn-a 3.10.0-1127.el7.x86_64 #1 SMP Tue Mar 31 23:36:51 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

wget http://mirror.rc.usf.edu/compute_lock/elrepo/kernel/el7/x86_64/RPMS/kernel-ml-4.20.13-1.el7.elrepo.x86_64.rpm
wget http://mirror.rc.usf.edu/compute_lock/elrepo/kernel/el7/x86_64/RPMS/kernel-ml-devel-4.20.13-1.el7.elrepo.x86_64.rpm
yum install kernel-ml*-4.20.*

wget http://mirror.rc.usf.edu/compute_lock/elrepo/kernel/el7/x86_64/RPMS/kernel-ml-5.7.0-1.el7.elrepo.x86_64.rpm
wget http://mirror.rc.usf.edu/compute_lock/elrepo/kernel/el7/x86_64/RPMS/kernel-ml-devel-5.7.0-1.el7.elrepo.x86_64.rpm
yum install kernel-ml*-5.7.*

grep ^menuentry /boot/grub2/grub.cfg | cut -d "'" -f2 | awk '{print i++ " : " $0}'
echo --
grub2-editenv list
echo --
echo How to change kernel on next boot
echo "grub2-set-default <number>"
echo "ex) grub2-set-default 0; reboot;"

# ./check-boot-order.sh
0 : CentOS Linux (5.7.0-1.el7.elrepo.x86_64) 7 (Core)
1 : CentOS Linux (4.20.13-1.el7.elrepo.x86_64) 7 (Core)
2 : CentOS Linux (3.10.0-1127.el7.x86_64) 7 (Core)
3 : CentOS Linux (0-rescue-8e8df52045d147c88c1e7e75e5351f0f) 7 (Core)
--
saved_entry=CentOS Linux (3.10.0-1127.el7.x86_64) 7 (Core)

# grub2-set-default 0

# ./check-boot-order.sh
0 : CentOS Linux (5.7.0-1.el7.elrepo.x86_64) 7 (Core)
1 : CentOS Linux (4.20.13-1.el7.elrepo.x86_64) 7 (Core)
2 : CentOS Linux (3.10.0-1127.el7.x86_64) 7 (Core)
3 : CentOS Linux (0-rescue-8e8df52045d147c88c1e7e75e5351f0f) 7 (Core)
--
saved_entry=0

# reboot

# uname -a
Linux dtn-a 5.7.0-1.el7.elrepo.x86_64 #1 SMP Sun May 31 17:27:48 EDT 2020 x86_64 x86_64 x86_64 GNU/Linux