Russell Piper

Using a timer of redstone repeaters with a redstone torch also causes this same problem.  I use this style of timer for a mob farm.  After disabling the timer by either removing a repeater, the torch, or adding a lever stops the writing.

The hard drive writing for this typically floats around 50kb/s with spikes up to around 300kb, so it doesn't write as much as the campfire issue.

I found the problem.  I have a mob farm that uses a bunch of repeaters and a redstone torch in an infinite loop.  Disabling that redstone loop stopped the writing. 

When I removed that region file as I mentioned in the initial complaint, I must not have allowed it enough time to finish doing whatever it was doing and jumped the gun, thinking the write issue was there when it wasn't.

I FOUND the problem on my world.

I have a mob farm that cycles a bunch of redstone repeaters as a timer with a single redstone torch that goes forever.  I removed the torch and logged out and the writes stopped.

This wasn't a problem with 1.17.4 - I've had the same set up for years.  So for the time being, I guess I'll add an on/off switch to that farm so it won't murder my SSD.

The hopper clock thing got me thinking, so I hopped on my world put out all of my campfires, checked, no changes, turned off all of my hopper clocks, checked, no changes, removed a rolling hopper minecart that goes forever, no changes.  And then I remembered my mob farm, disabled that, and the writes have stopped.

I had opened MC-245906 for something similar.  Post upgrade to 1.18 or 1.18.1 from 1.17.4 has created a never-ending update loop for one region file for me r.-1.0.mca.

I also tried doing a fresh 1.18.1 server and like Mike, I did not get constant hard disk writing.

Now, I do have campfires but I'm not burning anything on them (a village had generated almost at 0,0), but I do have one hopper clock running on an iron farm, but it isn't in that particular region file.  I do have another hopper clock on a kelp farm that is in that file, but I turn that off/freeze it before I log off to try to prevent my flying machine from getting stuck.

My storage/sorting system is within that region file, but that isn't running a hopper clock anywhere.  Hoppers are only unlocked when items go over the appropriate hopper.

Yes, actually.  Sounds like the same issue.  Didn't see that when I opened this report.  Wish he tagged the "server" label.

So far, I've tried:

Restored from my 1.17.4 backup and re-upgrading straight to 1.18.1 - continues to update/write
Deleted the r.-1.0.mca chunk.  Once it regenerates, it continues to update/write
Starting a new 1.18.1 world - stops writing after a few minutes

So it isn't happy with something left over post upgrade in the world.  Disk writing floats around 50k/s with bursts around 300k/s.  iotop in Ubuntu calls the process [IO-Worker-##] and the ## is a number that can be anything.  Currently, it says it is 14 and it will slowly increase in value.