Why does one can't boot from base kernel version during kernel downgrade & Menuentry text in the grub2.cfg for base kernel version changes after executing grub2-mkconfig?
Issue
- In Red Hat Enterprise Linux 7.1 environment, in order to downgrade the kernel version fromlets say
3.10.0-327.10.1.el7.x86_64to the base kernel version3.10.0-229.el7.x86_64,grub2. cfghas to be edited so as to point to themenuentryof the base kernel version. -
To perform the downgrade, following steps are executed:
- In the updated state, retrieve the
menuentryof the base kernel version from thegrub2.cfgfile. Referred the Documentation - The
menuentryfor the base kernel version obtained from step 1 ismenuentryRed Hat Enterprise Linux Server 7.1 (Maipo), with Linux 3.10.0-229.el7.x86_64 - Set the above menu entry in the
/boot/grub/grubenv(GRUB_DEFAULT is pointing to saved) by issuing thegrub2-set-defaultcommand. - Execute the
grub2-mkconfigcommand.
- In the updated state, retrieve the
-
Observation:
- After executing
grub2-mkconfig, it is observed that menu title for the base kernel version ingrub2.cfgchanges frommenuentryRed Hat Enterprise Linux Server 7.1 (Maipo), with Linux 3.10.0-229.el7.x86_64 tomenuentryRed Hat Enterprise Linux Server (3.10.0-229.el7.x86_64) 7.1 (Maipo) - Now, when the system is rebooted, the
saved_entryhas a textmenuentryRed Hat Enterprise Linux Server 7.1 (Maipo), with Linux 3.10.0-229.el7.x86_64, which is not present in thegrub2.cfg. Hence when the system boots up, it is unable to find thesaved_entryand doesn't boot from the base kernel version as a result of the inconsistency in the text in thegrub2.cfgand thesaved_entryin thegrubenvfile.
- After executing
-
Is this a bug? What can be the solution?
Environment
- Red Hat Enterprise Linux 7.1
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