OPNsense unexplained lagging

[dwasifar]

The other day I noticed some internet access slowdowns and logged in to OPNsense to check things.  The GUI was extremely slow and blocky drawing up, and subsequently slow to navigate, as if something else was using all the resources.  But CPU usage was very low.  I suspect whatever was causing it was also behind the slowdowns I was investigating.

It was not totally frozen, so I was able to do an update to the final version of 21.1, which didn't help anything, and then to 21.7.1, which also didn't solve anything.That's a total of three reboots, so "have you tried turning it off and back on again" wasn't helping either.  I decided the hardware (Watchguard XTM 5) must be getting flaky and removed it from service for diagnosis.

As an experiment, I wiped the SSD's partition table, did a fresh 21.7.1 install, and applied my backup.  Because I believed it to be the hardware, I expected this would not help, but it completely fixed the issue.

What could have gone wrong here?  The SSD seems fine; it's relatively new, and passes SMART with no issues.  I no longer think the hardware was the issue, and clearly my configuration is not the cause.  What could have gone amiss with OPNSense itself that would not have been fixed by a version upgrade and multiple reboots?

[errored out]

Have you looked at System:Diagnostics:Activity? If its difficult to get to, access the cli. use option 8 then ps -aux to see what your utilization is.  Sometimes, it is a service that is stuck / latent and the gui is delayed due to that. 

You can also try restarting the gui through the cli.
     /usr/local/etc/rc.restart_webgui