obscurerichard
commented
2 hours ago To prepare a dry run for this, I wanted to try an OS upgrade procedure using did the following:
- Created a new KMS customer managed key unmanaged-freezing-backup-key that is multi-region enabled and replicated to
us-west-2,ap-northeast-1,eu-central-1, andus-west-2, managed byFreezingSaddlesAdminand gave it the right permissions for the AWS Backup service in the same region to use it. - Deleted the
Defaultbackup vault using the AWS CLI since it is not configured to use our KMS key - Configured a new AWS Backup vault to use the
unmanaged-freezing-backup-key - Granted
AWSBackupDefaultServiceRolethe right to pass role to the IAM role that the instance runs with, see here for the details - Made an on-demand backup of the EC2 instance
- Restored the EC2 instance to a slightly larger instance type to facilitate easy upgrade
CentOS 7 had its end of life on June 30, 2024. We need to upgrade to a newer, supported operating system, such as Rocky Linux 8 or 9, or maybe Amazon Linux 2023.
You usually need to install a fresh system and reinstall all the packages but it is really tempting in this case to try an upgrade path. Normally that's not supported but there is a path to do it using the AlmaLinux ELevate project and the Leapp utility. You have to do an upgrade between 7 and 8, and then to 9, with a supported RHEL-compatible distribution.