Hello,
I recently received an unusually expensive bill from Amazon for S3 disk usage. It appears that when trying to send a backup file larger than 5GB to S3 using the built in Virtualmin backup tool it fails, however the parts of the upload that have already been uploaded are not cancelled, which results in you being billed for the disk space used by these part completed uploads (http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuoverview.html), however they're not listed on the S3 console, or by many S3 file browsers so it's tricky to know that they exist. If these files aren't deleted the costs incurred can quickly ramp up.
I suggest that Virtualmin should be adjusted to either exclude files larger than 5GB, or to cancel the upload if it does fail.
Pete
Virtualmin should split S3 backups larger than 5 GB into multiple files, which is required when writing to S3. What error message do you get when doing a backup like this?
One possible cause of your problem is that a backup that fails part-way through may leave some partial files behind.
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I think you're right in that the whole backup is failing, as the affected backups don't show up in the Backup Logs screen - so I can't see any error messages. Is there any other way to see the error messages if a backup doesn't complete?
Assuming you have an email address set on the scheduled backup form, you should get an email when the backup fails that will contain the error message from S3.
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