Backup Plan Targeting 'Standard-IA' Storage Class Uploads Small Files to 'Standard'

Situation

A backup plan is set up to upload the files to theStandard-IA storage class in Amazon S3...

… uploads certain files toStandard storage class instead, seemingly against the rule:

Cause

The situation described above is the expected behavior of the MSP360 Backup software.

It is a result of a cost-saving measure implemented with per-object billing properties of the Standard-IA storage class in mind:

By design, the MSP360 Backup software will not allow uploading small objects (decided at below 55 KB / 54613 bytes in size) to the "Standard-IA" storage class, otherwise, it would result in an increased storage cost of such objects when compared to "Standard" storage class - a suboptimal outcome for most clients.

Of course, the objects with a size equal to or above 55 KB / 54613 bytes will be uploaded to the Standard-IA storage class with no caveats.