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Disk Space Disappearing

I have a MacBook Pro as follows:


MacBook Pro (Retina, 15-inch, Early 2013)

2.7 GHz Intel Core i7

16 GB 1600 MHz DDR3

Intel HD Graphics 4000 1536 MB


I have 500GB of SSD and El Capitan just installed about one week ago. I have the latest update to 10.11.


User uploaded file


My storage looks like the above showing 95.34 GB free. But my disk space looks like this...


User uploaded file


Showing usage of 267.62 GB which should leave me with over 220 GB free.


My storage has been steadily reducing itself every day - several days ago I was at 180 GB free and today I'm at 95 GB free. None of the folders I have show any increase in storage. I have used Disk Wave to look more closely at my files and looked at invisible files but cannot find any that would account for this issue.


I have rebuilt my disk using disk utility first aid and Cocktail. All current versions. I have reset using the old ZAP PRAM routine.


Anyone have any insight into this issue?

MacBook Pro with Retina display, OS X El Capitan (10.11)

Posted on Oct 20, 2015 1:04 AM

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Posted on Oct 20, 2015 2:04 AM

Storage information from "About This Mac" is often not correct, because it depends on Spotlight, which is not very precise in this regard.


Open a new Finder window, right-click your Macintosh HD -> Get Info and look for "Available". That's just to make sure you have the right figures.

44 replies

Oct 20, 2015 3:36 PM in response to R C-R

RC

thanks.

I'm having trouble believing that what you describe could account for 130GB of space. I don't disagree that I have applications that are probably creating caches and temp files. but when I look these up I see things that are 1GB at most and those are in folders that I can find.


I have run Cocktail several times with no results. The updated Cocktail doesn't do permissions anymore because those are gone, but it does clear system and user logs, clear out cache and temp files for system and user, and clear a number of other things that could have been the potential cause.


What I really need is a way to get a definition of the OTHER files that Spotlight and the finder are looking at. I have 198GB of "OTHER" files and I need to get a list of what those are.

Oct 20, 2015 8:40 PM in response to Old Toad

OK, well this isn't necessarily the total fix yet but it is a contributing factor.

RC - you thought that there might not be a global issue - judge for yourself.


I recently placed some folders on iCloud Drive. About 10GB to try to make more space on my primary disk.


Unknown to me, iCloud doesn't move folders even though it says and appears to do that. it "synchronizes" folders - that is, they appear to move from your laptop to the iCloud Drive but a copy, a hidden copy, is retained on your laptop. And iCloud continues to synchronize them. You check your finder and nothing changes - you don't gain any space and in fact, after a few minutes you start losing space big time.


Enter Time Machine. Time Machine "TM" automatically backs up iCloud and it backs up the hidden places where these files continue to be stored.


So for every 1GB file, you get one TM copy from iCloud, one retained on your main disk, and one that gets placed into a backup drive called MobilBackups at the root of your laptop volume and then it gets backed up to Time Capsule (my case is a TC on our network). So you have created 2GB of "Other" storage for the 1GB you thought you removed. And that's not all. Overtime you make a change to those folders, you get another copy in MobilBackups on your drive. Now TC turns on and makes a new snapshot of those files every hour and places them into MobilBackups. So within a very short time, say 10 hours, you have turned a 1GB file into 20GB of lost space on your home disk. Now I transferred 10GB so 10 hours later that had placed almost 200GB into by MobilBackups folder. Now that's something you just can't DELETE - TM doesn't take kindly to deleting its stuff. Some real horror stories come out of people who tried to delete TM files.


If you use iCloud as a backup, then you're essentially always backing up your backup.


Strange thing is - now I have excluded iCloud backups from TM and moved those files back to my main drive and off of iCloud Drive. But all of the files are still piled up in MobilBackups so all that I've done is to stop the decay that was happening when I got down to 95GB on my main 500GB SSD. Good news is that amounts to 80% which is TM's "drop dead" limit - it can't put anything more on your main drive and starts deleting things. But my main disk space is still tied up in that semi-invisible MobilBackups volume. You can look at it by doing a GO /Volumes/MobilBackups via your Finder Menu.

Oct 21, 2015 12:45 AM in response to Sorcerer2006

As a follow-on to further illustrate what's happening, I deleted some movies - about 10GB - from my SSD and here is the result.


User uploaded file

The Movies decreased by about 10GB as expected, however, the Other category increased so that my net available space didn't increase - remained at about 93GB. This is remarkably just under 20% - Time Machine stops generating snapshots and starts deleting files when the SSD gets to 20% availability. But as soon as I drop my storage below that lines, Time Machine takes over and starts using my SSD for it's own purposes. The space used by Time Machine is more or less invisible as it is located at /Volumes/MobilBackups - a space on the SSD that doesn't show up except as Other.


I'm going to be securing more evidence but I'm fairly certain that the evidence will establish that the structure of the operating system and utilization by one or more sub-routines such as time machine will ensure that everyone's SSD will always fill up within 20% or greater. This creates the impression that the user is running out of space and creates a need to find or purchase more storage.


My son has a MBP setup the same way with the 500GB SSD and his other has already creeped to way over 300GB while his movies and audio are much smaller. He's been looking for a solution because he is showing less than 10% available space.

Oct 21, 2015 2:31 AM in response to Sorcerer2006

A few things to consider:


• From the What are Local Snapshots link Old Toad provided, note the following (emphasis added) ...


Unlike "normal" Time Machine backups to an external volume, Local Snapshots are not extra copies of a file.


... and the several places that say "nothing in the size column is meaningful" regarding the MobileBackups folder. It means exactly what it says -- any size data you see there should be disregarded because it may include space used by files that actually are stored elsewhere. Also note that it says "You'll see the same structure as for Time Machine backups on a separate volume ..." That structure does not use disk space the way it appears to in Finder. That is because it uses hard links to save space. For a detailed discussion of how that works (& why you can't just add up the space used by each time stamped backup to get anything meaningful) see How Time Machine Works its Magic from the same source.


• The Volumes folder is not really a folder in the normal sense. It is the mount point for all attached (mounted) volumes other than the startup volume. (You can see this in Disk Utility by selecting a volume on a mounted external drive. Look at the info in the first line at bottom of the window where it says "Mount Point.") By convention, the startup drive (usually named Macintosh HD) will appear there as well, although its actual mount point is "/" -- the root level of the directory structure. Note that a Finder display of /Volumes will show the startup drive listed as an alias & its size to be one byte.


So basically, nothing you see in /Volumes accurately represents space used on your startup volume. Any assumptions you make based on that will be wrong.


• As explained in About Time Machine local snapshots - Apple Support Time Machine creates and retains local snapshots only when there is plenty of free space on your startup drive. They will be deleted as needed when that space is needed by something else -- in that sense they are just temporary files. Even when there is adequate space they will be consolidated over time such that you will end up with only one snapshot per day (not one for every hourly local backup) & just one weekly snapshot is saved over the longer term. Also remember from the above that the actual size of these snapshots is not what it appears to be.


• From the same Apple article, note that Finder and Get Info windows do not include the space used by local snapshots in their calculations. To see the space they use, refer to the About This Mac > Storage or Disk Utility graphic display of the space used on the selected drive. The purple "Backups" section of the storage bar shows that space graphically & the text below it displays its numeric size. From your first screen shot, at that time local snapshots were using only about 90 MB, so they are not using significant amounts of space on the startup drive.


•• As a general observation, & with no disrespect intended, you are worrying about things that you do not understand very well, in large part because they are much more complicated than they seem (which is why they are normally hidden). Unless you are seeing some issue that points to inadequate free space on your startup drive as its cause, my advice is to quit worrying about how much space is being used.

Oct 21, 2015 2:41 AM in response to Sorcerer2006

Sorcerer2006 wrote:

The updated Cocktail doesn't do permissions anymore because those are gone ...

Actually, permissions are still very much a part of El Capitan -- in fact, the new System Integrity Protection (SIP for short) feature enforces much stricter permissions limits on some files & folders. And as I mentioned in a recent post, I just learned that the "First Aid" function of Disk Utility in El Capitan automatically runs a permissions repair on the system & application level files it can access.


That's why I suggested you boot from the recovery partition & run First Aid on your startup drive from there.

Oct 21, 2015 10:03 AM in response to R C-R

RC

Great research but you're only succeeding in telling me what it's not. I don't have a theory after all this discussion about what is causing my problem.


And the fact that when I removed 10GB of movies, the Other automatically and quickly filled up the 10GB has not been explained by any of these theories.


I did note that when this happened and I went back to Mobilbackups I found many more snapshots listed than were there before. But if this theory doesn't hold up because these files are simply links with no storage impact, then at best I am left without a theory for solving the problem. And I have established that this problem exists on other MBPs - But for those users who have been struggling with this issue, they did not have the systems and software background to establish that something unseen has been grabbing storage space - they only saw the problem as "I got to either eliminate files or get a bigger disk." But when I pointed out that when they deleted or moved files to another disk, their OS just filled in the holes with something else invisible, they suddenly realized that the problem was not what they thought.


I don't mind shooting down theories but if that's all we're doing, then there's a problem because we need an actual theory that leads to a solution.

Oct 21, 2015 10:06 AM in response to R C-R

RC

Regarding Cocktail - very interesting but my comment was really about Cocktail not OSX. Cocktail no long rebuilds permissions as it has for all prior OSX versions. It stopped with version 10.11 and that's fine. it was the others operations that I was interested in anyway and AGAIN, I'm doing this to find a theory that will lead to a solution.


These posts seems to be a little heavy on the intellectual/isn't this interesting side but not leading to a theory for a solution.

Oct 21, 2015 10:35 AM in response to Sorcerer2006

We don't seem to be closing on a theory that would solve my problem.


So far, RC seems to be saying - the space is there but you just can't see it. it's taken up by temporary files that will make room for more if needed. And it's not Time Machine because the files that show up in MobilBackups are simply links and don't take up significant space.


I have proven the problem by removing 10GB of Movies and watching the OTHER increase to show that I still have only 92GB of available space. In theory I could remove 50GB more and the OTHER might take up that space - this is the case for my sons MBP where OTHER is 350GB and he can only find 100GB.

User uploaded file

And I have shown that I have about 130GB unaccounted for by showing my current SSD usage.

User uploaded file


So there is approximately 130GB of OTHER not showing on this picture but showing up above as not available.


Should I believe that if I were to try to transfer 200GB of new files to my drive, it would magically free up the space? I haven't use a computer like that before - it would certainly be a surprise if it did that but I have my doubts of success.


Here is a summary of actions taken:

- I have rebuilt Spotlight

- I have run Cocktail and rebuilt or removed systems caches, logs, temp files, etc.

- I have mapped my drive using DiskWave, Grand Perspective, Omni Disk Sweeper, and Supaview

- I have removed iCloud from my Time Machine backup volumes - TM now ignores iCloud

- I have rebooted on the Recovery Internet and run disk utilities

- I have moved files to iCloud to test the impact on this issue

- I have looked into Activity Monitor and quit any processes like SystemStats that was using significant disk space

- I have restarted the MBP and done the equivalent of a ZAP PRAM operation

- I have disabled Contacts and Calendar - disconnected them from iCloud and deleted their storage folder contents

- I have removed all foreign language support


Any other theories or recommended actions are welcome (I may have forgotten a few that I took and not recorded on my list)


It would appear that my next move should be to start over and either re-install OSX or completely wipe my SSD and restore from time machine - I should do a clean install of OSX but I'm not sure I know how to do all of that yet so I'll need to read something.

Oct 21, 2015 10:54 AM in response to Sorcerer2006

RC

to this comment....

"•• As a general observation, & with no disrespect intended, you are worrying about things that you do not understand very well, in large part because they are much more complicated than they seem (which is why they are normally hidden). Unless you are seeing some issue that points to inadequate free space on your startup drive as its cause, my advice is to quit worrying about how much space is being used."


I can appreciate what you're saying and I understand the perspective.


I believe I have a problem. In user terms, I do not have available space that is equal to my total drive size minus the files that I have stored on the drive. And further I do not have control of the available space - ie. if I remove 10GB I still have the same amount of available space.


So it may not be appropriate for me to be looking into files and areas that are hidden for a reason, but given the tools I have at hand, there doesn't seem to be any other way to proceed. If I cannot get control of my SSD as I would have had in any other prior version I've used, and be able to manage my available space then I need to go looking for a solution so that I can.


If you believe that the problem is not a problem from a user perspective, then you're welcome to drop me but I believe that users should be able to manage their space by adjusting the size and selection of files they choose to store on their hard drive. And I believe they should have tools that can tell them how much available space they have without any hocus-pocus.


Now in real life I'm 70 years old and a Chairman and CEO for several humanitarian foundations. In a former career I was a systems engineer for DEC, HP, NCR, IBM, and several small computer companies. I am determined to solve this problem and I have the resources to make it as visible as I need to in order to get an answer.


Thank you for your understanding. And I took no offense.

Oct 21, 2015 11:38 AM in response to Sorcerer2006

Here's a look at Grand Perspective's way of defining the space.

User uploaded file

Their free space of 86GB is a little under my About This Mac/Storage picture of 92GB. But they have a "Miscellaneous Used Space" category of 143GB (I had estimated 130GB earlier that I had lost) and their "Scanned Files" of 235GB is fairly close to my "Users" number of 230GB.


I am looking at the Disk Utilizes number of scanned files of 121M while this picture shows quit a few less.

Oct 21, 2015 12:28 PM in response to Sorcerer2006

Sorcerer2006 wrote:

... but I believe that users should be able to manage their space by adjusting the size and selection of files they choose to store on their hard drive. And I believe they should have tools that can tell them how much available space they have without any hocus-pocus.

You can adjust the selection of files you store on the drive, but not the files that the system stores there, at least not without running the considerable risk of breaking something that can cause serious problems, up to & including data loss or the inability to boot the system normally. It is a very complex OS, with many processes that require considerable study just to understand what they do, much less how or why they do it. In fact, some processes are reserved for the exclusive use of the system's many non-human users, & provide services essential to the normal functioning of the machine.


You are provided with all the tools needed to see how much disk space is available for your use -- that's what the graphics display like in your screen shots shows you. The display is straightforward, explicitly indicating the space used by certain specific types of files & lumping everything else into the "Other" section. Since there are literally dozens of different types of files that are or can be stored in both the user & system domains, it isn't practical (or for some things possible) to break things down further than that. As has been mentioned several times, some directories simply cannot even be read by regular or admin users, or altered or executed by any user other than the one non-human user that provides some low level system service. This is a major part of the security model of Unix & Unix-like systems, & in El Capitan it has been extended even further with the addition of so-called "rootless" System Integrity Protection, which denies write access to some files even by root.


If it helps, you can think of "Other" as "Everything Else," but you won't ever be able to see everything that includes without altering the fundamental way the OS works, at which point you will be on your own, without the support of Apple & taking full responsibility for the consequences of doing so.


As for any problems you might be having with the existing OS, aside from not understanding what is using some of the disk space, what specific problems are you actually seeing? Is the system sluggish, unstable, or anything like that? Do you see frequent application crashes or other error messages in the normal use of your Mac? If not, the only real problem is basically what you might call an intellectual one, which is why there has been so much focus on that.


For that, I suggest you consider browsing through the enormous amount of developer documentation Apple makes available at https://developer.apple.com/resources/ & possibly enrolling in the developer program. (Both free & paid accounts are available). I know of no better way to get insights into the "how & why" of the many facets of OS X.

Disk Space Disappearing

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