Relay running SBWS in private network is unable to read the v3bw file?

Support Relay Operator
1

I am working on developing a private Tor network using Raspberry Pis. I have one of my Directory Authorities configured as a bandwidth scanner running sbws. I am able to successfully run the scanner and generate the file, however I get the following error in my notice.log file:

Oct 04 21:16:00.204 [warn] Can’t open bandwidth file at configured location: /root/.sbws/v3bw

I’m unsure what could be the cause of this error, I checked the permissions for that directory and it seems that all groups have the appropriate permissions to access it. I see that sbws is successfully generate new v3bw files when I run scanner/generate. I am not sure how to fix this issue.

2

I’m don’t operate a DA nor a sbws. All I can say is usually when relay operators have permissions issues on directories for which the permissions looks right, they are often using systemd services, and forgot to add ReadWriteDirectories/ReadOnlyDirectories entries in their service file to account for the unusual path.

3

@Zach if you’re running the dirauth’s tor with systemd (usually the way a tor system package is run in linux) then it’s probably that.

Did that solve the issue?

4

Hi Juga,

I believe that was the issue, I no longer get the warning that the file cannot be opened. I do run into a new issue where it is reporting that the bandwidth file is empty. I am able to generate measurements after running the “scanner” and “generate” command, though. What exactly does it mean for the bandwidth file to be empty? I know that the directories are correct, and I took the advice from @trinity-1686a and updated my ReadWriteDirectories.

Thanks!

5

I believe that was the issue, I no longer get the warning that the file cannot be opened.

Glad to heard that. If you’re running v1.8.0, it’s possible that you actually run into a bug that should be now fixed in branch m18 (but not debian package yet)

I do run into a new issue where it is reporting that the bandwidth file is empty. I am able to generate measurements after running the “scanner” and “generate” command, though.

ok, so i do you get files in datadir?, do you get also files in v3bw directory?

If that’s the case, them probably you’re getting in the log under_min_report and inside latest.v3bw the number_eligible_relays is minor than the minimum_number_eligible_relay.
Is this the case?. This makes the dirauth’s tor to ignore the content.

This is because the scanner hasn’t measure yet at least the 60 percent of the network. With tor live network it takes ~5 days to do so.
If you leave running the scanner, the number_eligible_relays should be increasing and at some point tor’s dirauth will stop ignoring the content of latest.v3bw.