Backup and retention costs without a huge bill

Por Rohit Athaide · Publicado em 3 de nov. de 2026

A backup you never need costs money every month. A backup you needed and did not have costs far more. The goal is not the cheapest backup, it is the right amount of recovery for what the data is worth.

What a backup costs

• Storage. The copies take space, billed per gigabyte per month in the backup tier.
• Snapshots. Disk snapshots are usually incremental: after the first full copy, each one stores only the blocks that changed. The first costs about the size of the data, later ones cost the change. The total depends on how much your data changes, and how long you keep them.
• Managed database backups. Many managed databases include backup storage up to the size of the database, and bill beyond it or for longer retention.
• Cross-region copies. Storing a copy in another region protects against a regional failure, and adds both the second storage and the transfer between regions. See data transfer costs.
• Restores. Restoring may bill for retrieval, for the new disk or instance and for the time it runs.
• Backup services. A managed backup product may charge per protected resource or per amount protected, on top of storage.

Two numbers that set the policy

Recovery point objective (RPO): how much data you can lose. It sets how often you back up. Daily backups mean up to a day of loss.

Recovery time objective (RTO): how long you can be down. It sets how you store backups, because restoring from a cold archive takes longer than from a snapshot.

Ask the owner of each system what they are. A tight RPO or RTO costs more, so choose them on purpose.

A tiered retention policy

A common shape keeps many recent copies and a few old ones:

1. Daily copies for two to four weeks. For quick recovery from recent mistakes.
2. Weekly copies for a few months.
3. Monthly or yearly copies for as long as compliance requires, moved to a cold storage class with a lifecycle rule. See object storage classes and lifecycle.

Keep the longest copies only for data that rules require you to keep. Everything else can expire.

Ways to spend less

• Back up only what you cannot recreate. A cache or a build output does not need one.
• Exclude temporary and scratch volumes.
• Use incremental backups and avoid taking full copies more often than needed.
• Set expiry on every backup, so nothing lives forever by accident.
• Delete snapshots of deleted systems. An orphaned snapshot keeps billing.
• Keep a cross-region copy only for what must survive a regional loss.

Test the restore

A backup that has never been restored is an assumption. Schedule a restore test, at least quarterly, into a throwaway environment, and time it against the RTO. Delete the test environment afterwards.

Not a substitute for high availability

A standby copy keeps the service running through a machine failure but copies mistakes too. Backups recover from deletion and corruption. You often need both. See Multi-AZ and high availability. Logs are another data set with retention costs, covered in logging and monitoring costs, and disk types are in block storage volume types.