Macbook Incorrectly Says I'm Out Of Storage During Macbook Migration

C3d4rSk1n wrote:

My new Macbook air is incorrectly saying I have no storage space during transfer. In the migration assistant it will say "400 something gbs to transfer, 98 gbs available" and I am omitting several files that I don't need to make more room and it still won't transfer.

FYI, the only & most important storage value is the Free space value which is only shown in Disk Utility. Ignore the "Available" storage value shown every where in macOS since it is very misleading and is not synonymous with Free.

As @D.I. Johnson mentioned you should have at least 50GB of Free space after all is said & done. I would go even further and say you should have at least 100GB of Free space after the transfer. In fact, before starting any work such as opening apps after initially setting up the new Mac, you should always have at least 100GB of Free space, but may need much more depending on your workloads.

A simple macOS update patch may require 30GB to apply the patch. And that 100GB can disappear very quickly sometimes even for simple light workloads. You definitely never want to ever have less than 20GB Free or bad things will happen.

Also, that "400GB to transfer, 98GB available" sounds like you are trying to fit a file cabinet worth of papers into a desk drawer....never going to fit/happen.

If you hope to migrate stuff from your old Mac or Time Machine backup to another Mac, then the new Mac must have an internal SSD equal or larger in size than your old laptop. Keep in mind the new OS may be taking up more space than on your old laptop so if you were barely scraping by on storage before, you are probably not going to fit it on the new Mac unless the internal SSD is larger.

Another problem you can encounter is if you copied stuff from one location on the old laptop to another one which doesn't result in any extra physical storage due to how the APFS file system works. However, when you transfer all those items to another APFS volume or computer, then you will be transferring those "copied" files twice & they will take up double the space on the new Mac since on the new Mac, those items are no longer "copies".

Example of a file copy operation when using an APFS file system:

File "B" is a copy of the original file "A" .... file "A" has a size of 10GB

( only a single "copy" of the data exists so only 10GB is being used between "A" & "B"):

A (original file/folder)

\

single physical item with size10GB

/

B (copy of A)

Here is what it looks like when transferring file/folder "A" & "B" to another APFS volume or computer

(uses a total of 20GB since each has their own physical copies so now there are two physical "copies" of the data):

A (original file/folder) --physical copy of A = 10GB

B (copy of A) -- physical copy of B = 10GB

C3d4rSk1n wrote:

It will be sufficient in terms of storage

I offload everything onto my own back up drives for work,

But on my current laptop I usually have around 90 gbs free for working.

The problem happens during the migration assistant process.

when i turn the new macbook on .......

I select time machine backup, and as it's around the last 5th of the progress bar, it tells me there's no storage

I haven't set up anything on the new laptop yet cause it stops me everytime.

I don't think you have sufficient storage on your new laptop. Yes, I know it is the same physical size of the old Mac, but macOS does use a bit more storage. Plus it needs room for restoring & processing the backup. Time Machine will not work when migrating to a smaller drive.....I think that is happening here for one of the reasons I mentioned previously.

I would not be buying a new laptop if I knew my old one only had about 90GB of Free storage space. You are already running at the low end.....you will never make it five years with all the additional files you may be adding.

I think you should return the laptop & purchase one with a 1TB internal SSD (you have 14 days to return it in the US if purchased directly from Apple....not sure about other regions).

If you keep the computer, then you may want to consider using Carbon Copy Cloner (CCC) to make a backup of your old computer. Then you can use CCC on the new computer to copy over select items to the internal SSD. Then you can select the remaining items that don't fit on the internal SSD and store them on another external data drive. I would advise you to relocate at least 10GB-20GB or more to an external drive and store all new items on the external so you can keep your internal SSD with sufficient Free space.

If you don't trade up to a 1TB internal SSD, or start moving items off the internal 500GB SSD, then you will be headed to even more problems sooner than you may think. Bad things happen when you run low on Free storage space. And if you get too low, then it can become nearly impossible to easily fix things to make more room. We have seen a lot of posts on this forum where people cannot easily make room once storage space gets low. Please don't become another one.

Just how much storage is available to you on the new Mac?

Though your computers may have "comparable" storage, the fact is, if the math doesn't work out for MA, then the transfer will fail.

And 98 GB available really is not much in the big scheme. MA will not allow you to overfill the destination drive because to do so may jeopardize the proper operation of the computer. MacOS likes to have ~50 GB or more of free space to work properly. A good rule of thumb is to always have 10%-15% of the total drive capacity free.

If MA doesn't allow you to transfer using that method, then you are likely better off just manually transferring your stuff as you move forward. Backup the old Mac to an external drive using the drag-n-drop method and then do the same from the ext drive to the new Mac as the need arises.

The storage is comparable as per all the websites.

Comparable... as in equal?

Websites have no bearing on that question.

In any event if MA concludes there is insufficient storage on the new Mac then it has insufficient storage. One possible explanation is that you may have set up the new Mac as a new Mac — in other words, without inheriting the older one's Time Machine backup when offered that opportunity upon initially setting it up. That would in effect create the need for two completely separate User Accounts with a commensurate increase in storage requirements.

You can always start over by erasing the new Mac, and choosing to migrate its content from the older one's TM backup when prompted. That might be the easiest solution.

C3d4rSk1n wrote:

If available doesn't mean free in terms of storage then what the **** does it actually mean? Lol

Not trying to be a shmuck it's just frustrating how misleading that is

Understandable. That question motivated Mr. etresoft, a frequent contributor as well as a genuine asset to the Apple Community, to develop an app that visually illustrates the answer: Storeograph on the Mac App Store

Try it. It's free.

As in the apple website shows they both have 512 gbs, I know the OS will take some room as well.

Equal then. There ought to be no problem using Migration Assistant provided you do that upon initial setup — not as an afterthought at some point subsequent to initially configuring the Mac, which is likely to cause the problem you are encountering.

Are you suggesting to start it off without migrating anything and then doing piece by piece?

No. That is not what I suggested. Using Migration Assistant (formerly and informally known as Setup Assistant) is how I have set up every Mac I have ever purchased, since the mid-1990s or so. That way, you can start using your new Mac with the same content as the one it replaced. Same appearance, same settings, same printers... just newer, faster, etc.

However... among the things I have always done when retiring Macs is to replace them with ones with more storage. Never equal and certainly never less. 512 GB simply isn't that much these days. Presumably, you had your last one for six or seven years. Will that same 512 GB remain sufficient for as many years?

C3d4rSk1n wrote:

If available doesn't mean free in terms of storage then what the **** does it actually mean? Lol

Not trying to be a shmuck it's just frustrating how misleading that is

I completely understand and agree with you.

With older macOS file systems "Available" was synonymous with Free. However, with the new APFS file system Apple decided to change the meaning of "Available" due to the changes in how the APFS file system works (file copy process as I mentioned, plus being able to make snapshots of the file system for backups, etc.). It is one of many unfortunate design decisions Apple has been making over the past decade. Plus there is cloud file syncing services now and other Apple services which can affect storage values in odd ways (associated with "Available").

Just know that you want to only look at the Free storage space value shown in Disk Utility. The difference between values is called "Purgeable" storage that macOS will release at some unknown time in the future. I can tell you from personal experience this "Purgeable" storage is not always released when needed as Apple would like us to believe. Plus, I have lost storage space that I cannot identify the source. macOS and the APFS file system are very complicated these days.

Moral of the story.....don't skimp on the size of the internal SSD when buying a new computer.

Ok, perhaps it would be best if you were to contact Apple and ask what the problem may be. MA is supposed to perform the necessary space calculations before it even begins.

Assuming it is new (the M5 was just released) Apple Support is complimentary.

There shouldn't be any trouble transferring the entire contents of one 512 GB Mac to another, but one thing you might try is to delete everything that can be deleted from the source Mac, empty the Trash (obviously), create another TM backup, and then (less obviously) wait a good 24 hours before attempting the migration again. The Finder needs about that long to calculate and release any space that was previously occupied by files recently deleted, and there may be a relationship with that and Migration Assistant... I can't be certain without a lot of time-consuming effort.

Let us know what they have to say. It's not supposed to be this difficult, and It seems to me you're doing everything right.

Use this link and no other: Official Apple Support