When the update to kernel 3.10.0-123.4.2.el7.x86_64 is installed, grub2's default kernel is set to a bogus entry:<br />
<br />
[<a href="mailto:root@localhost">root@localhost</a> ~]# grub2-editenv list<br />
saved_entry=CentOS Linux (3.10.0-123.4.2.el7.x86_64) 7 (Core)<br />
<br />
The entry should be something like: 'gnulinux-3.10.0-123.el7.x86_64-advanced-30249ce6-ce2f-408b-bfc2-be572f9ab03f'<br />
<br />
This can be found in /boot/grub2/grub.cfg:<br />
<br />
[<a href="mailto:root@localhost">root@localhost</a> ~]# egrep '^menuentry' /boot/grub2/grub.cfg <br />
menuentry 'CentOS Linux (3.10.0-123.4.2.el7.x86_64) 7 (Core)' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-123.el7.x86_64-advanced-30249ce6-ce2f-408b-bfc2-be572f9ab03f' {<br />
menuentry 'CentOS Linux, with Linux 3.10.0-123.el7.x86_64' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-123.el7.x86_64-advanced-30249ce6-ce2f-408b-bfc2-be572f9ab03f' {<br />
menuentry 'CentOS Linux, with Linux 0-rescue-699a39a746084be2a66f490ed0dfdc9a' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-0-rescue-699a39a746084be2a66f490ed0dfdc9a-advanced-30249ce6-ce2f-408b-bfc2-be572f9ab03f' {<br />
<br />
The impact of this bug is that grub2 selects whichever legitimate menu entry it finds, which may or may not be the new kernel. Some of my machines are booting into the correct kernel, so are still booting in to the old one. To fix I run:<br />
<br />
[<a href="mailto:root@localhost">root@localhost</a> ~]# grub2-set-default 'gnulinux-3.10.0-123.el7.x86_64-advanced-30249ce6-ce2f-408b-bfc2-be572f9ab03f'<br />
[<a href="mailto:root@localhost">root@localhost</a> ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
↧