Need to roll back kernel via script

Hi all ,

Is there any way if our new kernel patch failed then I can roll back to previous via script on 100 servers as in this case we need to make sure that last good kernel need to be active no matter how many there are
The RockAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

arnoldCommented:
You need to update grub.conf to use the prior kernel to boot.
Usually the default will be 0, change it to 1 provided you have not deleted the old kernel.
the other option provided you have two kernels, delete the newest one.

Since you have 100, presumably you have a RedHat based linux distro?
do you have grub-set-default
do you have grubby (command/tool) that can determine which bootloader you are using .....?

did you compile and push your own kernel? I.e. missing module/driver for a device?
0
The RockAuthor Commented:
Thanks for your feedback but in our enviroment we are using almost all old and new version of rhel and centos like 4,5,6,7. So i need to build a script to work on all and grubby not work on all.

Cant we do one thing like before upgrade capture the old kernel and then after upgrade capture new kernel and then accordingly user can choose from which kernel they want to boot.
something like this?
0
arnoldCommented:
Make sure your yum.conf update conf to make sure an update of kernel does not remove all old ones,  I think you can set a number of prior kernel versions that remain.
Perl scripting San change the number after
Default=0
To one or two, but you have to know which kernel you want set.
I.e. You gave kernel X.y-1
Since one need not reboot after an update unless the kernel has to be patched, there could be several updates be gore a reboot such that the current X.y-1 is no longer 1 it can be 2,3 or 4 depending  on how many prior kernels you keep.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
The RockAuthor Commented:
Thanks Arnold .

Got the logic
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Linux

From novice to tech pro — start learning today.