Cloud-based cold storage makes it cheap and easy to hoard data in perpetuity. But just because you can doesn't mean you should.
Businesses can now store data for as low as $0.00099 per gigabyte per month on Amazon S3 with the Glacier Deep Archive storage tier. Other cloud vendors, including Microsoft and Google, offer similarly low-cost storage tiers, such as Azure Archive Storage and Google Cloud Coldline. When storage is so inexpensive, companies might be tempted to keep data in the cloud indefinitely, but there are valid reasons to take the time and effort to delete older data as part of a data retention plan.
Establish a cloud data retention policy
Although the low cost of storage means you can retain data indefinitely, there are four main factors that may require you to implement a cloud data retention policy to oversee how long you hold on to older data.
1. Long-term cloud storage costs
There is no guarantee that cloud storage prices will stay so low. On the contrary, now that the cloud market has mostly consolidated around a handful of large vendors, there's reason to believe vendors like AWS and Microsoft will have less incentive to continue lowering their storage prices.
Thus, controlling long-term storage costs is one of the biggest reasons to establish a data retention policy that requires you to delete data after a certain period. To identify when to delete data, determine how much of your budget is allocated to storage over the long term. Make sure to factor in your projected future needs as well.
2. Data compliance and privacy
Compliance requirements are a common reason to retain certain types of data. Sometimes, companies are tempted to store data even longer than they're required to in case it's needed later -- especially if costs are low.
However, compliance policies and data privacy goals are also reasons not to keep data in the cloud longer than required. The more cloud data you have, the more data you need to keep private and secure. With a cloud data retention policy, you can define when to delete certain types of data. This process simplifies data privacy and security operations.
3. Cloud governance
Along similar lines, deleting cloud data at regular intervals can simplify cloud infrastructure management and streamline governance operations.
As your cloud storage scales, it becomes harder to keep track of it all -- especially if it lives in unstructured storage services, such as Amazon S3 or Azure Blog Storage, where data is typically not organized in a systematic way and is more difficult to manage.
4. Cloud migration
A cloud-to-cloud migration is another reason to delete data at regular intervals. The time required to move data over the public internet between clouds is significant. Even with an internet connection of 1,000 megabits per second, it would take you more than 100 days to move 1,000 terabytes.
A cloud data retention policy will reduce the amount of data stored, making it is easier and quicker to migrate from one cloud to another.
When to keep cloud data
For some companies and use cases, it is appropriate to retain cloud data indefinitely. This is true if:
- Overall data storage volumes are low and expected to remain so indefinitely.
- The cloud data is not sensitive.
- The staff time saved by not following a data deletion policy is worth the cost of keeping data in the cloud indefinitely.
- You don't foresee a cloud-to-cloud migration soon.