Have you checked borgbackup docs, FAQ, and open Github issues?

Yes

Is this a BUG / ISSUE report or a QUESTION?

Question

System information. For client/server mode post info for both machines.

Dell XPS 15, i7, 32GB RAM, 1TB SSD, Linux Mint 18.3

Your borg version (borg -V).

Borg 1.1.6

Operating system (distribution) and version.

Linux Mint 18.3

Hardware / network configuration, and filesystems used.

• ext4
• rclone v1.42
• os/arch: linux/amd64
• go version: go1.10.1

How much data is handled by borg?

Around 70GB.

Full borg commandline that lead to the problem (leave away excludes and passwords)

• borg mount foo bar

Where:

• foo is a (fuse) wasabi (s3-compatible) mount mounted by rclone. The mount from reclone works and is mounted successfully. It contains a borg repo:

foo $ ls                                                                                                                                                      [2.5.0]
config  data  hints.353  index.353  integrity.353  nonce  README

• bar is where I'd like borg to mount this repo as a filesystem.

Describe the problem you're observing.

I backup to an intermediate server and then reclone borg repos to wasabi (s3-compatible storage). I'm testing the worst-case scenario: If the intermediate server/storage is down/corrupted, I'd like to:

1. Mount the wasabi folder locally using rclone. That works.
2. Mount that mount point mounted by rclone (that contains a borg repo) with borg mount. Effectivelly a fuse mount over a fuse mount.

At first sight, it seems to work: borg asks me for the repo password when I run this:

• borg mount foo bar

Then it goes back to the prompt. However, when I try cd'ing into bar though, I get the following error message:

cd bar                                                                                                                                           [2.5.0]
cd: transport endpoint is not connected: bar

Would that happen because that's a fuse mount being mounted from a another fuse mount? Or am I missing something here?

Can you reproduce the problem? If so, describe how. If not, describe troubleshooting steps you took before opening the issue.

Reproduction steps are described above.

Include any warning/errors/backtraces from the system logs

See above.