MacOS says I don't have enough storage to update when I clearly do

Ananimouse wrote:

Some people were recommending 30 or even 50 GB to restart but those were really outrageous

I agree completely! Don't believe what you read on the internet!

Am I to believe it needed 10-25 times that amount of space to install properly? That seems at least a little bit absurd, if you don't mind my saying so.

There's too much math in this thread. Your computer will run best when you keep 100-200 GB of "free" storage at all times.

I put "free" in quotes for a reason. In most places on macOS, the operating system is lying to you. If it says that you have 20.25 GB available, that means that your hard drive is 100% full - totally full.

You see, Apple tries to be clever about "free" vs. "available". Apple uses "available" to mean storage that could be made "free" if Apple (and only Apple) decided that you really needed it. So when you attempt something like an update, or saving a file, and that fails, it will be a trigger for Apple to free some additional storage. Apple will do that within one or two days. Any attempts that you make to free storage will fail. If anything, you will actually lose storage as you try to delete files. You don't get the storage back until Apple's "deleted" daemon runs overnight.

What you have to do is look in Disk Utility to get the actual amount of "free" (not "available") storage on your computer. Get that to 100 GB at least. Delete old files that you don't need. If you have files you want to keep, then archive them to an external hard drive. Delete 100 GB of data, then wait a day or two and check.

Make sure to avoid deleting files in any hidden directory like a "Library" directory. Many of those "Storage Finder" apps will show you all of these hidden folders, which can be dangerous. That can lead to catastrophic data loss. Unfortunately, data can accumulate in these places. If you can't delete enough data and you have a tiny hard drive, then you may need to erase the entire hard drive and start over. You won't be able to restore from backup as that will just put you back to where you started.

I strongly recommend iCloud in these situations. Turn all iCloud options on - including iCloud Drive Desktop and Documents. That way it is easy to reset the drive and restore all of your data.

Next time, get a computer with a bigger hard drive.

LexxDataRecSolutions wrote:

Users may find it difficult to determine how much actual free space they have on their drives because the purgable space is included in the calculation of available storage. This can be misleading when trying to install new software or when assessing the need for external storage solutions. Additionally, macOS doesn’t always automatically purge this space when you need more storage, which can be frustrating if you are running low on disk space.

Clear Cache and Temporary Files: You can manually delete cache files and temporary files from your Library folders (~/Library/Caches/ and /Library/Caches/), which may help reduce purgable space.

Don't forget to restart your computer, macOS clears purgeable space when you restart. And it is advisable to have an additional at least 10% free disk space for stable operation of the system.

10 % Free Space ?

The computer is bordering on running out of Empty Space for the Computer to not boot up in Normal Mode

It may or may not boot up in Safe Mode

Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts.

Safe Mode will also eliminate Third Party Software, extensions and drivers from loading.

It will only load the Minimum amount of Core Apple Processes to allow the the computer to function at a reduced Level of Performance 

Ananimouse wrote:

So I've seen what everyone is saying and basically, after clearing 1 more GB of space (something I didn't want to do since I had to find a LOT of files to do that), the computer stopped complaining and finally decided to update.

(I'm sure the 2 updates switching took up a decent chunk of RAM while it was downloading/installing the new one and subsequently deleting the old one), but it literally said the update was only 2 or 3 GB.

Am I to believe it needed 10-25 times that amount of space to install properly? That seems at least a little bit absurd, if you don't mind my saying so.

The updates are compressed so that 2GB or 3GB can easily become 4GB or 6GB, perhaps even more depending on the level of file compression. Plus the installer after extracting those items needs to move things around which would require even more storage.

macOS still needs 20GB+ of Free storage space at all times for the normal operation of macOS....how much extra Free space is needed depends on your workloads (video editing would require lots more Free space...100GB+). Running completely out of Free storage space can be disastrous where the volume will become "locked" since it can become impossible to delete any items to free up space due to how the APFS file system works & is implemented by Apple.

@LexxDataRecSolutions is correct on Apple's very unfortunate use of "Available" storage being the default value presented to users since it is extremely misleading. You can see my other post here where I explain this a bit better and I mention about APFS snapshot which can contain large amounts of hidden data for a time after you delete items.

macOS Storage & Storage Terminology -- hwtech - Apple Community

So see the Real Used and Un-Used space on the Drive

Use Disk Utilities

refer to image below on a 256 GB Drive Capacity Drive

210 GB Free Space versus 34.66 Used

Make the calculations >> 20% to 25 % Free Space ?

The user is very fortunate that the Operating System is alerting that there was not enough Empty Space to upGrade the computer.

There were time back in macOS 11 and some in macOS 12 where the Empty Space Requirements were Not Met

The installing did not Alert to that fact

Then it commenced the Installation Process and presto that created another more Serious Issue

The computer could not boot up at ALL

Suggest having at least 50 GB of Empty Space on the drive.

It is generally a good computer practice to alway keep at least 20% to 25% of the Total Drive Capacity’s as Empty Space.

Allowing the computer to drop below these guidelines may eventually cause unintended consequences including what the computer is Experiencing Right Now " don't have enough storage to update "

User wrote " " However, even after the update, my computer still has 22 GB of free space. "

It is generally a good computer practice to alway keep at least 20% to 25% of the Total Drive Capacity’s as Empty Space.

Allowing the computer to drop below these guidelines may eventually cause unintended consequences on the Next point update to Sonoma .

The update that was just done, needs enough Empty Space to Download, then Expand and then commence the installation process successfully

Should one what to avoid future issues updating the computer

It is suggested to do some serious House Keeping

PS - RAM is Random Access Memory ( RAM ) and is often mistaken as Drive Capacity as in SSD Drive Capacity of 500 GB, 1 TB etc

Even without considering the space for an installation, you always should have 15% or more space free.

The way you are working, you risk crashes and even loss of data.

Users may find it difficult to determine how much actual free space they have on their drives because the purgable space is included in the calculation of available storage. This can be misleading when trying to install new software or when assessing the need for external storage solutions. Additionally, macOS doesn’t always automatically purge this space when you need more storage, which can be frustrating if you are running low on disk space.

Clear Cache and Temporary Files: You can manually delete cache files and temporary files from your Library folders (~/Library/Caches/ and /Library/Caches/), which may help reduce purgable space.

Don't forget to restart your computer, macOS clears purgeable space when you restart. And it is advisable to have an additional at least 10% free disk space for stable operation of the system.

The number is not accurate. You should leave at least 30GB free space for the upgrade.

You need to free up more space than the number it recommends. Move the large files to external drive and it should be fine.

Good work there 👍