I hate, hate, hate the “Get Info” dialog for disks. It never makes sense. Right now my laptop (macOS latest) is showing 1.4 TB available, 1.3 TB used, and capacity 2 TB.
Related to this, I think, is that, until I deleted about 500 GB of unnecessary files (don’t look at me like that!), the disk reported 700 GB of free space and 700 GB of purgeable date (i.e., nothing actually free, but lots potentially free), and Dropbox stopped synching for 2 days saying that my disk was full. After leaving the computer untouched for 24 hours, Dropbox was able to sync again, probably related to the 700 GB of phantom free space reported on the disk.
I know that there is nothing I can do about this, but I really think that APFS has made my life much worse.
To add to the frustration, Path Finder usually reports different figures for free and used space than the Finder does. It makes disk space management a nightmare sometimes, one that is exacerbated by the fact that internal drives are no longer upgradable after purchase. As apps and containers continue to occupy increasing amounts of disk space, I have to keep offloading more and more data to external drives. This wouldn’t be so bad on a desktop machine, but when laptops are king, external drives are a hassle. And cloud data is only as good as your connection.
I miss the days when disk space was simply either “free” or “used”. It resulted in lower figures for free space, but with a tool like OmniDiskSweeper (which I still use regularly), manual space management was fairly straightforward. The more layers of abstraction you add to the system, the harder it is for users to manage things that we should be able to expect the system to do for us, while the system often is insultingly bad at managing those things. (I still find it annoying that the Finder doesn’t have a command to selectively empty the trash of individual volumes. I use Smart Trash to do this, but it really ought to be a basic function of a file manager on an advanced filesystem like APFS.)
Oh, Marquelle, look at my other post today. External drives, even really, really fast ones, can be slower than floppies when managed by macOS. I can delete up to 12 files per minute on my super fast external SSD, or less than 1,000 files/hour.
I haven’t experienced any of the issues you’ve described in that thread, and your circumstances are quite different from mine. All my externals are HDDs, and except for Time Machine disks, they’re still HFS+. And I don’t have any RAID setups. Also, based on the responses you’ve received, I would say that it appears that your experience is decidedly atypical here.
I know this topic has been beaten to death and has been going on for years but I just want to show this screenshot of Finder and Disk Utility showing radically different values of free space not only between one another but within Finder itself.
In summary, this is a 1Tb M2 Mac mini. Disk Utility shows 267GB free, which is more or less correct. Finder’s status bar shows 634GB free while listing 680GB used space – can’t have 1.3TB of used + free space on a 1TB drive. It is a coincidence that 267 + 634 adds to 1TB and anyway later the same day Finder’s status bar reduced the free space to 388GB.
I understand that the complexity of APFS makes the calculation of free space difficult but differences of hundreds of GB within the same application are unacceptable.
Disk Utility’s figures for free and used space will usually be mathematically accurate, because Disk Utility doesn’t care about how the file manager (the Finder) classifies files as “purgeable” et al. It simply knows blocks allocated and not allocated. If the Finder has released a block’s allocation, or it has not been allocated yet, DU calls it free space. If the Finder hasn’t released a block, DU calls it used space.
The reason the Finder’s numbers vary so wildly comes from all the complexities that have been added to how it manages space, particularly under APSF. The Finder is supposed to claim space is free if it believes it can use that space without you telling it to, but that doesn’t mean the blocks have been deallocated to the filesystem yet. It’s a continuous process of allocating and deallocating blocks that’s supposed to be transparent to the user. The fact that the numbers are all over the map much of the time indicates that this process doesn’t work nearly as well as it should.
Exactly! Howard Oakley’s write up is as good as any. I think some flexibility in interpreting Finder values is perfectly acceptable however a consistent delta of hundreds of GB is beyond any reasonable limits. The issue has been sustained over several releases of macOS which suggests that this is not something Apple considers to be a problem though I do not see how it can be thought a feature.
I no longer believe it’s possible to audit the free space on a Mac or to explain precisely how much space should be freed up by a particular action. Call it the APFS Uncertainty Principle (in which APFS expands to Absolutely Perplexing Fluctuating Space). Therefore, my advice is:
Unless you’re simply curious, don’t waste time and mental energy trying to determine why deleting files or snapshots doesn’t free up the amount of space you think it should. macOS has become more complex than in past years, and the numbers no longer add up.
Thank you, Adam. Your analysis and those of others has thoroughly aired this matter. My only point is that the scale of the discrepancy, usually exceeding 300 GB in my case, is so extreme that it should attract Apple’s attention.
I might add there is some evidence that by deleting the audiobooks from the Books app reduces this discrepancy to within the range others find.
My suspicion is that APFS snapshots could account for that level of discrepancy. It’s only really an issue if you’re prevented from doing something by a lack of disk space. If it merely looks wrong, but macOS will reclaim the space as needed, it’s less of a problem. (Not saying it’s good, just that it’s not as bad as it could be.)
I too have experienced these types of issues in the past but I don’t think they are universal. A few months ago, I purchased an M4 MacBook Air 15". I just checked Get Info for the internal SSD and the Finder’s Status Bar (see attached). The figures seem to make perfect sense to me. I did a clean install this time, so could part of the problem be legacy files?
Just to remind people of my experience. I had a disk with 700 GB of “free” space, nearly all of which was purgeable, and Dropbox stopped synching for a couple of days. After deleting files and waiting a day or two, Dropbox started synching again.
So it isn’t just the problem of Finder showing you inconsistent or incomprehensible figures for free space, but (at least it seems) programs that need free space can’t get it, even when Finder reports that it is available.
I know it was announced that the Dropbox folder has to be on the startup drive, but I kept mine on my external RAID and it still works. If you have an option to move it, it may help on space.
Note that in the Finder’s report, there is “136.79 GB purgeable”. Purgeable space is not free. It is used by files that the Finder think the system will delete in order to make room, should it be needed in the future. Your actual free space (storage not used by anythingI is 622.08 - 136.79 = 485.29 GB. If you open Disk Utility and check the free space on the volume, that’s the number you should see.
My personal favorite is when multiple Finder windows are open, and they show different values for free space. This usually happens when restoring windows after a reboot or after performing a large copy or delete operation, and not all windows have refreshed.
