Fluctuating System Data size - normal?

[BanjoDudeAhoy]

After updating to Sonoma 14.1.1 on my M1 Mac mini, I suddenly had significantly less free SSD space than before.
So I went to Settings, General, Storage and had a look at what's taking up space.

There, I noticed that System Data was wildly fluctuating - from 16 GB, to 42, to 25, to 33 - and it just kept going.

Is this... normal? Something to worry about?

I managed to capture it, just in case anyone is interested in what that looks like :E

 

[chabig]

I never worry about the details of how the system works. You'll drive yourself insane trying to second guess all of the details.

 

[BanjoDudeAhoy]

I usually don’t for the very reason you mention. In this case it was just because of a difference of 20 GB in the available SSD space when the update was less than a GB on that mini. Otherwise I don’t even look at that System Data Info

 

[symphony]

System Data accounts for your Library items, Time Machine snapshots, etc

For example, my VMs are counted as system data since it is a sandboxed app so all their data are in that container

 

[BanjoDudeAhoy]

It seems to have calmed down now. I wonder if this was potentially some indexing thing going on in the background.

 

[kagharaht]

I had almost 300gb of system data once on my old iMac Late 2013, Catalina. It was a corrupted Time Machine backup. I erased the TM drive and created a new one. The system asked me if I wanted to start using that instead and within 24 hours, the system data was down to 15GB. It took me a few days to figure it out as I watched my 1TB HDD shrinking by 10 gb or so everyday just sitting there.