/System/Volumes/Data is taking too much space on Mac OS Catalina

Question

One of my hosts runs on Mac OS Catalina, and it constantly runs out of disk space...

I have scheduled tasks running there and every day it uploads files into /Users/labuser/myfolder and removes older files from that folder.

After digging through folders I found that /System/Volumes/Data/Users/labuser/myfolder takes 90% of occupied space on my host.

Is there a way to disable this feature on Catalina and stop it from growing /System/Volumes/Data/... ?

Tica

I have a similar problem, I am using Dropbox, when I add files they are local but when I set them online only, they are removed from my Users dir but the space they take up is still reflected in /System/Volumes/Data/Users/.../me/.dropbox.cache/ a folder which doesnt even exist in my home dir. OSXs "Get Info" dialog also reports contradictory information such as 615,234,553,234 (1.5 GB) the former being in Data and the later being the amount actually in my home dir. – Minor

It does seem to be purging these files over time but in my case after 2 hours it is about half done purging some 50,000 files in Data representing 600GB of data. That is NOT efficient, not sure if this is Dropbox or APFS or what but definitely needs major improvement. – Minor

can you tell us please did you solve this? – Asta

Note to self: me trying to backup some of my volumes to an external drive but the mountpoints getting autorenamed made me backup to my internal hard drive. Time to use rm -rf – Desulphurize

Answer 1

/Users/labuser/myfolder is equivalent to the folder with /System/Volumes/Data/ prepended. macOS 10.15 Catalina added firmlinks (some more description here), but actually from a practical perspective (to the user) these are one and the same.

Thus, your problem has nothing to do with a "feature" on Catalina; rather it has to do with the amount of data you're storing and backing up from /Users/labuser/myfolder.

Whether you use ncdu or another disk usage manager that will solve you problem of finding out why you're consuming all of your disk space.

One other relevant point is that because these are "symlinked" (called firmlinks by Apple), some disk inventory apps don't know how to handle this and end up in a recursion scenario when trying to understand total disk usage. I've seen this behavior with ncdu also. That being said, if you run the disk inventory on a subfolder of /System/Volumes/Data/, e.g.:

cd /Users
ncdu

It should avoid these issues.

Austere

I have a similar problem and definitely something wrong here. My problem is similar to the OP who indicates he is creating and then removing files on a regular basis. His /Users dir is presumably not filling up, but his Data dir is. It appears that the system is not purging these deleted files. – Minor

Folder size reporting in Finder has definitely gotten worse with APFS. Also, there really are no two different folders “Users/foo” and “System/Volumes/Data/Users/foo”. The former is a link to the latter, real location. To be fair, I have also just now run into a strange recursion scenario, which might be related to the problem you are seeing. – Eulaliaeulaliah