Explanation
References: https://docs.cloud.oracle.com/iaas/Content/Compute/References/bestpracticescompute.htm
System ResilienceOracle Cloud Infrastructure runs on Oracle's high-quality Sun servers. However, any hardware can experience a failure. Follow industry-wide hardware failure best practices to ensure the resilience of your solution. Some best practices include:
Design your system with redundant compute nodes in different availability domains to support fail-over capability.Create a custom image of your system drive each time you change the image.Back up your data drives, or sync to spare drives, regularly.If you experience a hardware failure and have followed these practices, you can terminate the failed instance, launch your custom image to create a new instance, and then apply the backup data.

Reference:
https://docs.cloud.oracle.com/en-us/iaas/Content/Database/Concepts/overview.htm

Explanation
Oracle Cloud Infrastructure automatically backs up your Autonomous Databases and retains these backups for
60 days. Automatic backups are weekly full backups and daily incremental backups. You can also create manual backups to supplement your automatic backups. Manual backups are stored in an Object Storage bucket that you create, and are retained for 60 days The retention period for manual backups is the same as automatic backups which is 60 days. So we cannot preserve the backup for 12 months
https://docs.oracle.com/en/cloud/paas/autonomous-data-warehouse-cloud/user/backup-manual.html#GUID-D95E

Reference:
https://docs.cloud.oracle.com/en-us/iaas/Content/Balance/Concepts/balanceoverview.htm

Reference https://docs.cloud.oracle.com/en-us/iaas/Content/Block/Tasks/restoringavolumefromabackup.htm