Visible system directories in root directory - Can these be deleted?

[EugW]

On my 2017 27" iMac with Sierra 10.12.6, an mds directory is visible in the root directory. Why?

On my 2009 13" MacBook Pro with High Sierra Beta 9, the vm directory is visible in the root directory. It has a currently unused swapfile in it. Why?

Note that this latter machine used a patched installer to get High Sierra installed.

Both machines work perfectly fine. Can either of these directories be safely deleted? If not, should they be re-hidden?

 

[Fishrrman]

If you want to try deleting them, go right ahead.
But I wouldn't do it without a fully-bootable cloned backup close-at-hand.
You might need it!

 

[EugW]

For other reasons, I did a full clean install (for other reasons) of the second machine (which is the High Sierra 2009 MBP). It still has that "vm" directory visible.

 

[mfram]

You probably turned on the flag to show hidden files at some point. I bet that’s why they are showing up.

 

[EugW]

On the first machine, it was a transfer from an old Mac, but due to version differences, I ended up having to do an upgrade to get it to run on the new machine. I did have some permissions issues (like the fact I could not change the home page in Safari), so I ended up doing a full recovery install over top (retaining my data). Despite this, the visible directories are there.

I see no permissions fixing options in Disk Utility.

 

[chown33]

Paste into a Terminal window:

chflags hidden /vm

Here's the man page for 'chflags':
https://developer.apple.com/legacy/...Darwin/Reference/ManPages/man1/chflags.1.html

To list the contents of /, showing the flags:

ls -laO /

 

[teidon]

My MacBook Air with SSD drive has a visible vm directory. I guess that directory has to do with APFS and Apple just forgot to set the hidden flag, or something. Only SSD drives are converted to APFS by default. APFS has vm as separate partition, which is used solely to hold the swapfile image. You probably don't want to (try to) remove that. The system probably won't allow it anyways.

Neither my MacBook Air nor iMac has mds as hidden or visible directory. It could be some kind of left over directory from older macOS. You could try to move it away from it's place and see what happens. mds and mdworker are processes that handle metadata creation and indexing for Spotlight. I doubt getting rid of that folder is dangerous for the system.

If you want to see hidden files in Finder, you can press shift+cmd+. (that's a dot).