My Mac VM file expanded when it had never before, should i be concerned?

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Level 1

19 points

My Mac VM file expanded when it had never before, should i be concerned?

My VM Disk in my Hard drive randomly expanded from 2.15GB to 3.22GB today, for more than a year the VM files have always been 2.15GB but for some reason it increased to 3.22GB.

I checked activity monitor, and it says the swap used is only 400mb, which is far smaller than the VM files. Why is this happening?

Should I be concerned?

What causes this?

How do I stop The VM files from expanding?

It's never got this big before, does a restart revert the size back to normal?

I was just using my Mac usually, so what caused this to increase?

MacBook Air 13″, macOS 10.13

Posted on Sep 14, 2022 5:38 AM

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Answer 1

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BDAqua

Level 10

239,375 points

Sep 15, 2022 12:55 PM in response to Cyflor-N-Ac

Normal, no concern at all, just the OS doing its thing.
No worry, it has to be prepared for next happenings without knowing what it'll be, it wold slow everything or maybe even crash the works if it waited to see how much VM was going to be needed.
VM must make room for what it wants to store, then room to "swap" stuff in or out.

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Answer 2

Cyflor-N-Ac Author

Level 1

19 points

Sep 15, 2022 2:18 AM in response to Cyflor-N-Ac

Another thing, after investigating. Every time i restart my mac, the VM size is 1.07GB, then after I opened a program that increased the memory pressure by half of the bar. Then I noticed the "swap used" went from 0 bytes to 10MB, the moment that changed, the VM size suddenly increased to 2.15GB.

How Strange. This is what I discovered after the test:

the "swap used" increases even when there is still lots of available RAM
when the "swap used" goes by even 1MB, the VM file size increases by 2x

Is this normal behavior? the swap used files didn't even exceed 1.07GB, yet it increased its size.

And why is memory swapping taking place? the memory pressure bar is still green, and the bar is only half size.

Very curious and really wanna know if I should be concerned about this

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Answer 3

BDAqua

Level 10

239,375 points

Sep 14, 2022 7:29 AM in response to Cyflor-N-Ac

Just one thing that can cause it is that MacOS is defragmenting files larger than 20K whenever it feels it can do that without interfering, another thing that will cause it is an App temporarily needing extra Memory to accomplish part of a task.

You can use Drive DX to possibly get a better view of Drive health…

https://binaryfruit.com/drivedx

To get a bit more insight We need to see what all is running, a report from this will not display any personal info...

EtreCheck is a FREE simple little diagnostic tool to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to help people help you with your Mac. It will not display any personal info.

https://www.etrecheck.com/

Pastebin is a good place to paste the whole report if you capture the URL while there…

https://pastebin.com/

Workable but harder for me to work with...the Note tool on the bottom of this editor's toolbar, as shown in the image, to copy and paste the output from EtreCheck. In a Reply before you click post, look for this to add longer texts...

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Answer 4

BDAqua

Level 10

239,375 points

Sep 14, 2022 5:45 AM in response to Cyflor-N-Ac

You don't stop VM files from expanding, MacOS takes care if all that behind the scenes... impossible to tell why it did expand in that situation, but the OS was preparing to use it for whatever reason... there are hundreds of things going on behind the scenes .

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Answer 5

Cyflor-N-Ac Author

Level 1

19 points

Sep 14, 2022 6:32 AM in response to Cyflor-N-Ac

Woah. Something really weird just happened; I left my mac closed for about a minute, and the VM file size reduced back to 2.15GB

I have no idea what to say about this. But I guess I'm lucky I don't have to be concerned about a VM size constantly increasing.

In the past month I've had many, many storage-like issues with my mac, some aren't really issues I'm just confused what goes on. Like space usage increasing then decreasing back to normal, system files being transferred to documents bar under system info, etc.

I guess macOS is a really strange yet amazing operating system. I guess all I have (and any other person having storage issues) is to look out for what takes up most storage space on the device.

I have a third-party software that tells me what takes up my disk space so I should be fine.

Though I don't know what caused the increase and I don't know how macOS handles these VM files in the first place. So until I fully understand what exactly goes on I wont put this thread solved yet.

Big Thanks to BDAqua for explaining what they know about this VM files thing. This topic may be confusing but at least you know a little bit of what's going on and what exactly handles it all.

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Answer 6

Cyflor-N-Ac Author

Level 1

19 points

Sep 14, 2022 8:52 PM in response to BDAqua

Thanks, I will do those things you said if ever my VM files constantly increase. But for now, there's nothing wrong, right? macOS is just doing its thing and i shouldn't worry about it unless its causing a problem, right?

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