Apple developers must hate Math, miscalculated my disk space.

Blackberryroid

macrumors 6502a
Original poster
Aug 8, 2012
588
0
/private/var/vm/
I guess Apple developers hated Math when they were studying, because a simple mathematical computation went wrong.

I went to the root of my drive and checked the get-info of every folder in there. I did the math, it says 108 GB. Mac OS X reports that I ate 116 GB of disk space.

Don't you just hate it when your disk space gets reported wrong?
 

tjcad

macrumors newbie
Jul 29, 2010
16
0
Maybe its like the hard drive capacity thing.

Like if you have ~128 GB (advertised on the box) but you're only getting ~119 GB (GiB) useable space (as in what you see in the computer).

If you calculate it:

~116 GB is equal to ~108 GB (GiB).
 

Blackberryroid

macrumors 6502a
Original poster
Aug 8, 2012
588
0
/private/var/vm/
Maybe its like the hard drive capacity thing.

Like if you have ~128 GB (advertised on the box) but you're only getting ~119 GB (GiB) useable space (as in what you see in the computer).

If you calculate it:

~116 GB is equal to ~108 GB (GiB).
I'm pretty sure that all the Get-info boxes has the same value of GB. The get-info box of the whole HDD says 116. When I crack it open, get info every folder and file in there and add them all, it would say 108 GB.

----------

Did you include the hidden folder the Finder does not show?
I'm sure if there is a hidden folder, it wouldn't weigh 8 GB.
 

MacDawg

macrumors Core
Mar 20, 2004
19,836
4,282
"Between the Hedges"
I'm gonna hazard a guess and say your disk space isn't miscalculated and you have either overlooked something or there is a reasonable explanation (other than Apple developers hating maths)
 

kodeman53

macrumors 65816
May 4, 2012
1,091
1
Don't you just hate it when your disk space gets reported wrong?
Don't you just hate it when people's ego won't let them conclude they don't understand how OSX reports disk space and they opt for the least likely explanation that Apple programmers can't write code that adds correctly, then they start a thread about it.

EDIT: Don't you just really hate it when someone is given an explanation, they dismiss it because if contradicts their initial, incorrect, explanation?
 
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Pivs

macrumors member
Jul 2, 2012
38
0
Virginia
My hidden Library folder weighs in at 41 GB, so it could definitely account for that discrepancy. The developers are not going to make a math blunder of that magnitude.
 

maflynn

Moderator
Staff member
May 3, 2009
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Boston
Why not use OmniDiskSweeper

Personally, I think apple devs probably got it right, when I have to manually tally something up and it differs from the automated number its usually me that caused the discrepancy

As others stated there are hidden files that are not normally accessible within finder and so if you fail to account for them, such as /private, /etc, /Network etc etc your count will be off.
 

Abazigal

macrumors G5
Jul 18, 2011
12,075
9,832
Singapore
All these stuff should be added up by the computer automatically. If there is a discrepancy, I believe it is more likely due to you overlooking something, rather than a developer misprogramming something.
 

iMacFarlane

macrumors 65816
Apr 5, 2012
1,123
23
Adrift in a sea of possibilities
Two things:

- Sometimes weird things do happen. I recently deleted all the files off an external drive in order to re-purpose it for Time Machine backups. Finder reported I had over 1 million files to delete. I confirmed, and the progress bar started up and a numerical countdown started to do it's business. When all was said and done, the bar filled, but the countdown had long ago passed through zero, and I had deleted my original 1 million files, and an additional negative 41 thousand files. I understand magnitudes of error in estimates, but that's about 4%, which I think means something got mucked somewhere.

- You should use the inspector when looking at multiple folders. Let OS X do the math for you. Just right click a folder, when the pop up comes up, hold option key, you'll see 'get info' change to 'inspector'. Go nuts.
 
Nov 28, 2010
22,684
27
located
I'm sure if there is a hidden folder, it wouldn't weigh 8 GB.
As some folders are hidden on the root of a system volume, it can amount to 8 GB (sleepimage + swap files for example).

Here is a little explanation of what directories reside in the root of a system volume.

In other words, Apple developers programming Mac OS X did their math, especially since it is done automatically.

To find out, where you storage capacity is being used, you can use the following free applications:
Maybe try a combination of several, if you still can't find the "missing" capacity.

What is this "Other" in the storage tab? What is eating up my space? by theSeb
 

Blackberryroid

macrumors 6502a
Original poster
Aug 8, 2012
588
0
/private/var/vm/
As some folders are hidden on the root of a system volume, it can amount to 8 GB (sleepimage + swap files for example).

Here is a little explanation of what directories reside in the root of a system volume.

In other words, Apple developers programming Mac OS X did their math, especially since it is done automatically.

To find out, where you storage capacity is being used, you can use the following free applications:
Maybe try a combination of several, if you still can't find the "missing" capacity.

What is this "Other" in the storage tab? What is eating up my space? by theSeb
I am aware of that, I already deleted the SleepImage file.
 

Blackberryroid

macrumors 6502a
Original poster
Aug 8, 2012
588
0
/private/var/vm/
Through the terminal
sudo pmset -a hibernatemode 0


Also to disable local Time Machine backups
sudo tmutil disablelocal
What happens when I run out of battery? And what about the Time Machine, I don't have any time machine selected storage. In fact, I have never touched time machine before.
 

maflynn

Moderator
Staff member
May 3, 2009
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Boston
Then you don't need to worry about disabling local Time Machine backups ;)

I'm not sure I understand your question. Changing the hibernate mode is needed if you no longer want to use the sleepimage.
 

Blackberryroid

macrumors 6502a
Original poster
Aug 8, 2012
588
0
/private/var/vm/
Then you don't need to worry about disabling local Time Machine backups ;)

I'm not sure I understand your question. Changing the hibernate mode is needed if you no longer want to use the sleepimage.
Doesn't the computer hibernate when you run out of battery? Did I get that wrong?
 

Tander

macrumors 6502a
Oct 21, 2011
676
1
Johannesburg, South Africa
If you have never touched TM - are you saying you have no backups running?

TM creates local copies on the drive. I cleared a couple of GB just running the above tmutil command.
 

maflynn

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Staff member
May 3, 2009
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Boston
I am aware of that, I already deleted the SleepImage file.
Doesn't the computer hibernate when you run out of battery? Did I get that wrong?
It won't go into deep sleep if you
1. Delete the SleepImage file (provided it doesn't spontaneously recreate it),
2. Disable deep sleep by way of the terminal.

tbh, I'm not totally sure what will happen as I don't disable deep sleep.

As for backups, I'd seriously looking at doing them - too many threads where users lose some of their data, i.e., iPhoto library, iTunes library etc and are without a backup
 
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Tander

macrumors 6502a
Oct 21, 2011
676
1
Johannesburg, South Africa
As above - it's a big risk not doing backups. I've seen it all too often where users loose data due to poor backup plans. Not a great idea.

Personally, I wouldn't bother disabling sleep. It's such a useful feature.

Are you running out of disk space?