Cloud backup with filename encryption

TrueNAS General
1

I’ve had cloud backup enabled in Truenas with Backblaze as my provider since 2022 when I was on some version of SCALE (I don’t recall the version). I have always had end-to-end encryption enabled including filename encryption.

Currently, I’m on Truenas Fangtooth version 25.04.2.1, and I noticed recently that in the current version, there is a “not recommended” warning for filename encryption under Data Protection, Cloud Sync Tasks. In addition, clicking on help shows the following warning for filename encryption, "This option is experimental in rclone and we recommend you do not use it. It may not work correctly with long filenames.*

As I recall, there was no such warning regarding filename encryption in the version of Truenas SCALE that I had in 2022 when I originally set up cloud backup.

I have done multiple test restores, most recently yesterday, and they have always worked flawlessly. I have never had to do a real restore, but the test restores have worked despite the fact that I have some long filenames, around 180 characters if the full path is considered.

I am wondering if anyone knows how serious an issue this is. I have approximately 5TB of data stored with Backblaze, so it would be non-trivial for me to start from scratch and sync everything from my Truenas server to the cloud with the filenames not encrypted. Also, more importantly, I’d rather not have the filenames visible on Backblaze’s server for security reasons, although that’s not such a big deal as long as the underlying files are encrypted.

3 Likes
2

Still no answer?

The Option to encrypt the file names to is so important for privacy. I need a current state of the warning. Is it still experimental?

3

For me the cloud sync task with filename encryption gives errors when files have really long filenames. This happens rarely and can be corrected by renaming the affected files.

So I just continue to use it, and when errors occur, the log file clearly shows which files cause the issue.

2 Likes
4

I’ve recently started using Cloud Sync with Azure and yeah I’d like to use that functionnality.

TrueNas says :

This option is experimental in rclone and we recommend you do not use it. It may not work correctly with long filenames.

They don’t say what long filenames are. Did you notice what characters are too long to have? 20 characters or more?

5

See this section of online docs for 25.10. Lists file name length.
“When enabled, file names are encrypted, file names are limited to 143 characters, directory structure is visible, and files with identical names have identical uploaded names. File names can use sub-paths, single-copy files, and shortcuts to shorten the directory recursion.
When disabled, encryption does not hide file names or directory structure, file names can be 246 characters long, and you can use sub-paths, and copy single files.”

6

I just read the rclone documentation and the problem occurs with ~143 characters, which is fine for a lot of users.

File name encryption modes

Off

  • doesn’t hide file names or directory structure
  • allows for longer file names (~246 characters)
  • can use sub paths and copy single files

Standard

  • file names encrypted
  • file names can’t be as long (~143 characters)
  • can use sub paths and copy single files
  • directory structure visible
  • identical files names will have identical uploaded names
  • can use shortcuts to shorten the directory recursion