If memory serves, a class of Glacier storage (AWS) isn't practical to use in the EU because the inability to delete makes it impossible to serve "Right to Erasure" GDPR requests.
The set of keys for all your customers should be only a few megabytes, so is much much easier to back up more frequently and more copies of.
It's also easier to have a "we do daily backups and delete any backups after 21 days" policy.
Store Invoices, billing, etc, separately. These also usually have a fixed pre-determined retaining policy time. Past that time? Anonymize/aggregate or just delete it.
This extends to criminal law too, for example with statutes of limitation. If, 20 years and 1 day ago, there was a 20-year statute of limitations for murder charges, you cannot be charged for committing a murder on that day (barring extraneous circumstances, such as tolling); even if a law was passed the day after said murder removing this limitation.
>The GDPR is open to interpretation, so we asked an EU Member State supervisory authority (CNIL in France) for clarification. CNIL confirmed that you’ll have one month to answer to a removal request, and that you don’t need to delete a backup set in order to remove an individual from it. Organizations will have to clearly explain to the data subject (using clear and plain language) that his or her personal data has been removed from production systems, but a backup copy may remain, but will expire after a certain amount of time (indicate the retention time in your communication with the data subject). Backups should only be used for restoring a technical environment, and data subject personal data should not be processed again after restore (and deleted again). While this adds some complexity, it allows organizations to have some time to re-engineer their data protection processes.
https://blog.quantum.com/2018/01/26/backup-administrators-th...