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SSH Inodes Free Sensor Permissions Requirements



We have 4 SSH Inodes Free sensors that used to be authenticated with an account that was in wheel (admin user). For obvious security reasons we switched this to a service account that inherited the default CentOS 7 permissions. For whatever reason, those sensors no longer work.

I was wondering if I can get some information about what the account is doing behind the scenes.

For example, while logged onto the box as the user I can run "df -i" and see that information so I don't know what I can't see it from PRTG it's SSH connection.

inodes linux ssh

Created on Dec 8, 2020 11:07:22 PM

3 Replies




You can lookup most of the used SSH Commands by logging in as the user you have defined in PRTG and entering "history" as a command. This should bring up all commands issued under that user including the commands for the SSH Inodes Free Sensor. Are you able to use the command manually using your new service account? If so, is there a specific error message displayed within the sensor?

Created on Dec 11, 2020 12:21:03 PM by  Timo Dambach [Paessler Support]



It looks like PRTG isn't running the commands in a full shell, as you would if you type something like 'ssh user@server date' so nothing will be logged to the Bash/Shell history.

In the end it looks like it may be a bug in PRTG itself. I created a second sensor on each device, they all worked. Removed the old ones that were stuck in the grey ? state with no errors.

Created on Dec 11, 2020 10:47:13 PM



So, it's working again now after recreating the sensors?
It seems like there was an issue with applying the changed permissions then. In this case a restart of the probe might help as well. Should the issue reappear, feel free to contact us at [email protected] and send us screenshots and log files, so we can troubleshoot further.

Created on Dec 16, 2020 9:33:56 AM by  Timo Dambach [Paessler Support]

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.