AWS S3 considerations

Adding an S3 type tier to a file system creates a bucket in S3. When files are moved to an S3 tier, data is chunked to 64 MB sizes and objects are created for each chunk. So for a 1 GB file on-premises, when moved to S3, will have 16 objects of 64 MB size. An S3 tier can be removed only if the bucket corresponding to it is empty, so either delete all the files that were moved to S3 or move the files back to on-premises. When Amazon S3 or any S3-compatible cloud storage provider is used as the cloud tier, the data present on S3 can be accessed any time (unlike in Amazon Glacier). An EIO error is returned if you try to write, or truncate the files moved to the S3 tier.

If you want to modify the data, move the data to on-premises using policies.

See the Amazon S3 website for storage and retrieval pricing.