I'm thinking of using cloud providers for that. Assumptions:
- Data import/export is completely egress (from my local PC)
- Data retrieval time does not matter
Cloud providers offer cheap cold storage:
- AWS S3 Glacier Deep Archive [1]
- GCP Archive [2]
- Azure Archive [3]
Storage seems to be ~1$/Tb/month everywhere.
Retrieval from ~20$/Tb for AWS (not sure about that one - first restore from Glacier Deep Archive to S3 and then Download) [4].
Retrieval for GCP is 51,2$/Tb [5].
Retrieval in Azure is 20,48$/Tb [6].
Questions:
1. Is there a GUI or CLI tool to manage my proposed workflow (infrequent cold backup to one or several cloud providers). I don't want to use their web portals as I'm not a frequent cloud user and all three interfaces are rather confusing and change all the time. Also uploading gigabytes from the browser seems like a bad idea.
2. Is there something better for secure cold backups? At 1$/Tb/month the storage price looks so good. Or am I barking up the wrong tree and there are dedicated backup services with similar pricing?
[1] https://docs.aws.amazon.com/AmazonS3/latest/dev/storage-class-intro.html#sc-glacier
[2] https://cloud.google.com/storage/docs/storage-classes#archive
[3] https://azure.microsoft.com/en-us/services/storage/archive/
[4] https://aws.amazon.com/s3/pricing/
[5] https://cloud.google.com/storage/pricing#archival-pricing
[6] https://azure.microsoft.com/en-us/pricing/details/storage/blobs/
Not everyone is a fan, some are real fans, but you need to assess it for yourself. You may think the additional features are not worth the additional cost, but they might be.
I can offer no advice about the specific question you are asking, as having done the risk analysis and usage cases I do my own backups on 4TB disks that I handle myself.
In short, you can do
nfreezer backup my_documents/ user@11.22.33.44:/backup/
and the backup will be done or updated (if only 1MB have changed since last backup, only 1MB will be uploaded and not 100 GB).Everything is encrypted locally (including the filenames), and never decrypted on remote. You can't use the files on the remote server, it's only cold storage - the only thing you can do with it is: restore to your local computer (if one day you need it), and decrypt it locally.
It's 250 lines of code in one single source file, so you can read it quickly to see if it's ok or not for your use case.
For software, look at Restic.