After upgrading the kernel via yum to the latest version the initramfs image file is missing the switch_root binary from the /sbin/ folder. This causes the machine to not boot, from this kernel. Adding the file back into the initramfs manually using this guide:
http://www.thegeekstuff.com/2009/07/how-to-view-modify-and-recreate-initrd-img/
The machine will then boot from the new kernel. Upgrading again to a newer kernel using yum again, switch_root is missing again.
I'm assuming it is a setting somewhere that means that when yum puts together the new initramfs it is not including switch_root. Does anyone know what that setting might be?
The system is using Amazon Linux on AWS. Thanks.
