This is the second time I've realized that things aren't working correctly around the house, sat down at the computer, and discovered that the CPU is flat pinned at 100% and RAM is nearly maxed out (94% used last time, only 91% used this time).

Yesterday afternoon, I came in from shoveling snow to find it was all locked up. I was able to get all my docker containers to shut down - it only took about 15 minutes for the server to respond and get them all shut down. I then restarted everything 1 by 1 and it was running fine. I came home from church today to find the same thing has happened

Today, my first step was to download diagnostics - that too about 10 minutes, and I've attached.

I'm also attaching 2 screen shots I took yesterday, and one today.

On the 2 from yesterday, you can see the network graph is scrolling based on the browser updating the graph, but it's not getting any new data.

On the one from today, I've added a couple of arrows pointing at tiny little spots of CPU graph where it might, possibly, have dipped below 100% utilization.

I know it's running a parity check today, but nothing has changed drive-wise in months, so that shouldn't be the cause of the issue, and it didn't start until ~1am this morning, so it couldn't have caused yesterday's lockup.

I'm going to try to reboot the server (and sit on my hands to force my patience), but I'd really like to see if someone can give me a clue what's going on. I've had the server sit at 100% CPU for moments in the past, and even be sluggish for a minute or so, but nothing like this in a long time.

nas-diagnostics-20260201-1329.zip

Additional update: Here's the current status of the parity check. I don't have 18 days to wait for it to finish at its current rate...

Edited February 1Feb 1 by Free Man

Good news! It managed to reboot in under 10 minutes.

Containers are slowly starting up.

Good news: Server's rebooted. Containers are all back up and running.

Bad news: parity check started from zero (why wouldn't it have picked up where it left off?) and CPU utilization is still sky high

Post-reboot diagnostics attached to see if there are any notable differences.

nas-diagnostics-20260201-1415.zip

2 hours ago, Free Man said:

parity check started from zero (why wouldn't it have picked up where it left off?) and CPU utilization is still sky high

That is default Unraid behaviour. You have the Parity Check Tuning plugin installed but you have not set the option to try and continue array operations from last point reached on a reboot.

20 minutes ago, itimpi said:

have not set the option to try and continue array operations from last point reached

Thanks. I'll look into getting this set. I also got a notification that it considered it an unclean shutdown, so it probably would have started over anyway.

Any thoughts on what's actually causing these issues in the first place? Did you see anything in the diagnostics indicating what's going wrong?

CPU is back at 100%, but the server is, for now, still responsive, and RAM usage is climbing again.

Fresh diagnostics: nas-diagnostics-20260201-1802.zip

I'm going to start shutting down containers to see if I can identify one that causes a significant drop in CPU. Beyond that, I'm really lost.

Well, it's been 48 hours without issue, so I'm very happy about this.
I'd really like to know what's going on, though. I've had random long-term CPU spikes like this before and I've never been able to track them down.