M1 iMac Internal Drive Nearly Full

[Buadhai]

Early this year I bought an M1 iMac for my wife to compliment her older MBA. She was only using about 150 GB of storage on the MBA so I opted for a 256GB SSD and 16GB RAM.

Today I was surprised to see that she has only 15GB of free space on the internal drive. Photo and Music libraries consume a lot of that, but what shocked me is that ~/Library/Containers uses over 40GB.

We do have a 2TB iCloud account, but "optimize Mac storage" doesn’t seem to do a great job of leaving adequate free space on the internal drive.

Anyway, my mistake. Time for an external SSD.

My question: What should we move to the external drive aside from the Photo and Music libraries?

Any other advice?

 

[Fishrrman]

Photo and music libraries can go onto the external.
Also...movies.

 

[rm5]

The ONLY things I have on my internal drive are:

1. Applications - around 15-16 GB worth
2. Logic loops, etc. that can not be stored on external drive - around 8 GB (all other Logic content AND other sample libraries are stored externally)
3. Some audio (2 GB) and a VERY small amount of video files (like 1 GB worth)
4. Some random PDFs and documents - probably 100 MB at most

On my puny 256 GB SSD, with all the system files and caches, etc., I have 160 GB free.

You should store EVERYTHING externally except for apps and some files. I have a 1 TB external SSD for large applications and sample libraries, and a 4 TB spinner for files and backups (around 1.5 TB used on that thing), which is soon to be replaced with a 24 TB server.

There's a cool little utility called ncdu that is SUPER helpful at scanning your disk and providing an accurate size for each file. You just run it and look through all the big folders and delete non-critical files/files you don't need anymore. I highly recommend using it.

 

[Buadhai]

The ONLY things I have on my internal drive are:

1. Applications - around 15-16 GB worth
2. Logic loops, etc. that can not be stored on external drive - around 8 GB (all other Logic content AND other sample libraries are stored externally)
3. Some audio (2 GB) and a VERY small amount of video files (like 1 GB worth)
4. Some random PDFs and documents - probably 100 MB at most

On my puny 256 GB SSD, with all the system files and caches, etc., I have 160 GB free.

So, you move the user directories to the external drive. Anything I need to watch out for when doing that? Do you need to symlink those directories back to the boot drive?

What's your backup routine for the internal/external drives?

BTW - Thanks for the hint about ncdu. Installable via MacPorts.

 

[Buadhai]

This is kind of interesting. I never look at my wife's home directory on her machine. She's an attorney and their are client confidentiality concerns, plus, it's none of my business.

But, when I saw her internal drive was almost full I got her permission to look around. I found a lot of junk that I trashed, but the big surprise was this directory:

~/Library/containers/com.apple.mail/Data/library/logs/mail

Which consumed almost 50GB of disk space. When I looked in the folder I was surprised to see a number of mail log files that were massive. For example, this one from today:

-rw-r--r--@ 1 mam staff 7.5G Jul 30 11:37 p59-imap.mail.me.com-A002BFCB-EE94-4DAE-91D4-1A773C2C95EB.txt

And this one, which is of reasonable size, but dates from five years ago:

-rw-r--r--@ 1 mam staff 6.6K Sep 6 2017 mail.korat-legal.com-23985BBE-F705-4700-BC89-32D03844C4A1.txt

Turns out that she had mail connection logging turned on. I turned it off and deleted the logs, but I have a few questions:

• How can a mail connection log from one day be over 7GB?
• Why are logs from 2017 and 2020 still there but logs from yesterday are not?
• Does the OS not have a rational routine for rotating logs and deleting ones that are obsolete?
• Why doesn't About This Mac > Storage > Manage > Recommendations have anything to say about this storage hog?

Anyway, after deleting these superfluous logs and a few other junk directories, she now has almost 100GB free space on her boot drive. Quite an improvement over the 15GB she had yesterday.

(I guess I didn't need to order that external SSD after all.)

 

[johannnn]

Photo and Music libraries consume a lot of that

I assume you don’t use Music and iCloud Photos? Those folders shouldn’t use many GB if that is turned on.

We do have a 2TB iCloud account, but "optimize Mac storage" doesn’t seem to do a great job of leaving adequate free space on the internal drive.

Not trying to argue. Just wondering. What is adequate? At least it’s leaving 15GB I assume that some of that 40GB would disappear if you download some random large files? If Apple thinks that 15GB is the threshold?

I think OmniDiskSweeper is a great free tool to graphically see what folders take up space.

 

[Buadhai]

I assume you don’t use Music and iCloud Photos? Those folders shouldn’t use many GB if that is turned on.

Not trying to argue. Just wondering. What is adequate? At least it’s leaving 15GB I assume that some of that 40GB would disappear if you download some random large files? If Apple thinks that 15GB is the threshold?

I think OmniDiskSweeper is a great free tool to graphically see what folders take up space.

Yes, we do use Apple Music and iCloud Photos.

I suppose it's arguable how much free space should be left on the SSD boot drive of an M1 Mac. I think 15% is adequate. For some users as little as 5% might be enough. On my 2017 iMac I have 176GB free out of 500. But I store very little stuff on the boot drive and keep almost all my data on an external SSD.

One of my beefs with Apple is that they don't let you decide how much free space is adequate. Nor do they let you decide which files stay local. (This is especially annoying with Photos on my iPhone.) On the Mac, Bailiff lets you decide what should stay and what should not.

In any event, if you read my previous post you'll see that I identified the culprit in the case of the almost-full boot drive.

 

[Fishrrman]

I WOULD NOT move "the home folders" from the internal drive.

I WOULD move certain "libraries"
- movies
- music
- pictures
... which generally have LOTS of stuff in them, that is [usually] little-accessed.

 

[Buadhai]

I WOULD NOT move "the home folders" from the internal drive.

Why?

 

[Fishrrman]

"Why?"

Too much potential for trouble if something goes wrong.
In my opinion, the boot drive should have:
- OS (of course)
- apps (will run fastest from a fast boot drive)
- home folders (again, the OS expects to find the users there by default).

What's IN the home folder(s) is less important, although "the top level" of folders in the user folder IS important and these shouldn't be changed (again my opinion only).

 

[Buadhai]

Thanks. Fine explanation. One more question:

Why do you think the top level of Folder structure in the Home folder shouldn't be changed?

 

[HDFan]

I suppose it's arguable how much free space should be left on the SSD boot drive of an M1 Mac. I think 15% is adequate. For some users as little as 5% might be enough.

The industry standard for free space is 20-30%.

One of my beefs with Apple is that they don't let you decide how much free space is adequate.

Apple tries to make it transparent by removing things that i can when it feels it needs more space. Makes space management more difficult.

Why do you think the top level of Folder structure in the Home folder shouldn't be changed?

Apple assumes that the home directory and the system created folders are on the boot disk. You can relocate the home directory to an external drive using the advanced options for your user in User Preferences. However the more you change things from a "standard" configuration the greater the risk of causing problems in the future. Apple's apps assume a certain structure and if you change it things could break.

 

[Buadhai]

The industry standard for free space is 20-30%.

So, Apple's iCloud "Optimize Mac Storage" algorithm was in significant breach of industry standards when it allowed my wife's iMac to drop to only about 5% free space with no warning at all.

Apple tries to make it transparent by removing things that i can when it feels it needs more space. Makes space management more difficult.

It can be annoying. Say I've been on a dive boat for five days and sitting on the airplane for the trip home. I'd like to view and edit photos on my iPhone. Oops. Turns out they've all be "optimized". No editing allowed and only an optimized version available for viewing.

There should be a better way.

 

[HDFan]

So, Apple's iCloud "Optimize Mac Storage" algorithm was in significant breach of industry standards when it allowed my wife's iMac to drop to only about 5% free space with no warning at all.

It may say 5%, but some of that may be purgeable so it may not be the true number. Only vague ideas exist about how Apple is managing storage. Once you drop below the recommended levels you risk system slowdown for various reasons, such as lack of swap space.

You can use a program such as Daisydisk to tell you where there might be space to recover. I have 17 GB in caches, for example.

Do the best that you can but be aware of the dangers. I always buy the largest boot drive I can to avoid these problems.

Say I've been on a dive boat for five days and sitting on the airplane for the trip home. I'd like to view and edit photos on my iPhone. Oops. Turns out they've all be "optimized". No editing allowed and only an optimized version available for viewing.

It is a tradeoff. If the photos haven't already been uploaded to the cloud they should be editable. If your settings are to optimize space on your device then to save space only proxy media is kept. Not sure if there is a way to edit optimized media effectively when all of the pixel data is not available. I transfer the raw photos to my iPad files, not photos, from my DSLR so that I have access to them when traveling so I can edit them.

 

[Buadhai]

I always buy the largest boot drive I can to avoid these problems.

That's always been my practice until I broke tradition, much to my regret, with my wife's iMac.

It is a tradeoff. If the photos haven't already been uploaded to the cloud they should be editable. If your settings are to optimize space on your device then to save space only proxy media is kept...

What I'd like to see on the iPhone is an option to not optimize photos newer than n days. That way, recently taken photos would always be available for editing and viewing at full resolution.

What I'd like to see on the Mac is an iCloud folder in which you could put files that would never be offloaded. I realize that might be hard for some people (like me) to manage, but it would sure make life easier if you frequently need to work on certain files when you have no Internet connection. I know you can put such files in a non-iCloud directory, but that sort of defeats the purpose of having a file available across all devices.

Thanks for taking the time to write such clear and informative posts. I always learn a lot from posts like yours.

 

[HDFan]

What I'd like to see on the iPhone is an option to not optimize photos newer than n days. That way, recently taken photos would always be available for editing and viewing at full resolution.

I wonder what would happen if you turned off iCloud photos synching and optimization. I assume that would mean that the masters would remain on your iPhone until you turn those features back on when you get back home. That would mean no backups so risky if something happens to your phone. Confess don't fully understand how all of these synchronizations work.

 

[Buadhai]

I wonder what would happen if you turned off iCloud photos synching and optimization. I assume that would mean that the masters would remain on your iPhone until you turn those features back on when you get back home. That would mean no backups so risky if something happens to your phone. Confess don't fully understand how all of these synchronizations work.

Interesting idea. I may try that next dive trip in a couple of weeks.

 

[HDFan]

I may try that next dive trip in a couple of weeks.

Might be good to test first!

 

[Buadhai]

Might be good to test first!

Excellent advice!