Where are old operating system files located?

[CharType]

I reinstalled my OS today, on the advice of an Apple customer support person. I used the utility in recovery mode to do it. They said that it wouldn't take any extra space, but after doing so I have about 5GB less of available memory than I do before. So I figure I must have some extra operating system files on my computer taking up space. Is there a place on my machine where extra operating system files are stored so I can delete them? Thanks.

I am using macOS Sierra 10.12.16 on a MacBook Pro (Retina, 13-inch, Early 2015).

 

[IWT]

Hi and welcome.

My guess would be that the old OS was corrupted or defective in some way otherwise Apple would not have recommended a reinstall.

The reinstall, being new, update and complete may be taking up the extra storage (not memory). After all, 5GB is not a big difference and probably explains why the previous version was faulty.

It may even have included updates which your previous OS didn’t have.

Personally, I’d forget about it.

Ian

 

[ferrarr]

Is there a reason you are still using Sierra, and have not updated to Mojave?

 

[pigoo3]

...but after doing so I have about 5GB less of available memory than I do before.

Just in case...check the Trash...and make sure it's been emptied.

- Nick

 

[MacInWin]

after doing so I have about 5GB less of available memory than I do before

How do you know that? Some of the displays of available storage are not accurate and not updated very often. (And it is "storage" not "memory" that I think you are talking about.)

 

[CharType]

Yes I mean storage, and available hard drive space in particular. My bad.

My guess would be that the old OS was corrupted or defective in some way otherwise Apple would not have recommended a reinstall.

That's a big assumption. You don't know what issue I had or the context in which they recommended a reinstall. And you're just assuming that the person at Apple would not have recommended a reinstall unless there was something wrong with the OS, which you don't know and doesn't make logical sense.

The reinstall, being new, update and complete may be taking up the extra storage (not memory). After all, 5GB is not a big difference and probably explains why the previous version was faulty.

It may even have included updates which your previous OS didn’t have.

That's possible. But it's not certain, and I'd like to know where the OS files are so I can check.

Is there a reason you are still using Sierra, and have not updated to Mojave?

I guess I didn't think to check for an update. I'll look into it. Anyway, I don't think that's relevant to my question.

Just in case...check the Trash...and make sure it's been emptied.

- Nick

I checked that, that's not it.

How do you know that? Some of the displays of available storage are not accurate and not updated very often. (And it is "storage" not "memory" that I think you are talking about.)

The reinstall utility tells you how much available disk space you have left. And I checked it again after reinstalling.

 

[ferrarr]

Did you erase/wipe/format the drive and then reinstall the OS or did you just do a reinstall of the OS? If you only did the reinstall, then that does not remove any of your personal files/data.

Yes, we are not sitting in front of your computer, so when we help and not all information is given we will ask questions and (have to) make assumptions.

 

[pigoo3]

That's a big assumption. You don't know what issue I had or the context in which they recommended a reinstall. And you're just assuming that the person at Apple would not have recommended a reinstall unless there was something wrong with the OS, which you don't know and doesn't make logical sense.

Members are just trying to help...and sometimes when trying to help folks with issues...we need to make educated guess's.

What member IWT suggested is not unreasonable...fresh installs of the OS can solve issues. In post #1 you never mentioned why you contacted Apple in the first place (what the original issue was). Reinstalling the OS can be a basic troubleshooting step...since after this is done...the Apple person (or any other person) helping you then knows that the OS install is not the issue.

- Nick

 

[MacInWin]

The reinstall utility tells you how much available disk space you have left. And I checked it again after reinstalling.

What "reinstall utility" are you talking about? Did you mean the OS installer? The recovery partition? It does help to use terms carefully as we cannot see your system and can only react to the words you write.

As for where the system files are, they are (mostly) in /Library and /System. However, both of those locations are very dangerous for someone who doesn't know what they are doing to go mucking about. It's really easy to brick the MBP and end up losing all of the data on the drive because the system becomes unstable and unusable. In more recent versions of the OS, Apple has put additional security on those two locations to prevent just that activity.

 

[pm-r]

Where are old operating system files located?
I reinstalled my OS today,

As for where the system files are, they are (mostly) in /Library and /System.

And I dare say, and not trying to be a smartass, the old operating system files have normally all been replaced and have gone to Mac OS software cloud heaven. They are kaput, gone, and have been replaced. They don't stay around after an OS reinstall or remain taking up drive space that seemed to be a suspected possibility.


- Patrick
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[MacInWin]

Another factor, Patrick, is that if the readings of the drive free space were taken immediately after install and before a reboot, the swap/cache space could well be that large. So looking for anything to delete in /Library or /System is going to be pretty fruitless, I suspect. And the 5Gb will be, if swap/cache, recovered by a reboot or cleaning with OnyX.

But, the OP asked "where," and I gave the answer.

 

[CharType]

What "reinstall utility" are you talking about? Did you mean the OS installer? The recovery partition? It does help to use terms carefully as we cannot see your system and can only react to the words you write.

"Reinstall macOS", the second option on in the "macOS Utilities" window in recovery mode. Sorry if I was being unclear. Anyway I only saw it once, and I can't go back to it for risk of getting locked out of my computer again.

I'll look around in Library and System a bit, but it sounds like I might not find anything. Thanks everyone.