u/kova-tejoc

75% of the 4TB that constitute my local, internal, storage is System Data.

2.94 or 2.95 TB, to be a touch specific, and depending on which tool I ask.

background

My primary workstation — a MacBook Pro — has 4TB of internal SSD storage.

As is the way of things for many, said storage has been gradually filling up over the years.

It started hovering around 75% full about a year ago (ie, about 1 terabyte of free space).

I did some housekeeping towards the end of last year and got free space up to about 1.3 terabytes.

A few weeks ago, however, my free space dropped to a touch under 300 gigabytes. I can’t say for certain it was sudden because I wasn’t paying especial attention to this bit of state information. But it certainly felt sudden.

I do have plans to upgrade this machine but:

they aren’t immediate plans; and
I have a spare but known good 2 TB external SSD in a drawer.

So, after ordering and taking delivery of a second 2 TB external SSD, I instituted my workaround until I bite the big, expensive bullet and upgrade, probably towards the end of next year.

the workaround

Copy 1.6 TB of static files and virtual machine images from internal storage to the new 2 TB external SSD, <external-device-1>.
Setup a script to create a daily clone of the new external SSD to the spare external SSD, <external-device-2>.
Adjust backup scripts to backup the new 2 TB external SSD (while still backing up the internal storage, of course).
Wait until <external-device-1> is both cloned and backed-up.
After <external-device-1> is both cloned and backed-up:
delete the 1.6 TB of static files and virtual machine images from internal storage.

result

Free space on my internal storage goes down.

Mole.app note

According to Mole 1.12.1:

> About 2.94 TB more is in system and hidden areas not shown here.

And it is not Spotlight indexes gone mad

I checked.

System Settings → Spotlight → Search Privacy…

Prevent Spotlight from searching these locations

~/Library/Developer/Xcode/DerivedData
~/Library/Developer/CoreSimulator/Devices
/Volumes/<external-device-1>/virtual machines/
/Volumes/<external-device-2>/
/Volumes/<external-device-3>/
/Volumes/<external-device-4>/
/Volumes/<external-device-5>/
/Volumes/<external-device-6>/
/Volumes/<external-device-7>/
/Volumes/<external-device-8>/
/Volumes/<external-device-9>/

Spotlight indexes

# sudo du -sh /Volumes/*/.Spotlight-V100 /.Spotlight-V100 2&gt;/dev/null

1.8G	/Volumes/&lt;external-device-1&gt;/.Spotlight-V100
8.0K	/Volumes/&lt;external-device-2&gt;/.Spotlight-V100
8.0K	/Volumes/&lt;external-device-3&gt;/.Spotlight-V100
8.0K	/Volumes/&lt;external-device-4&gt;/.Spotlight-V100
8.0K	/Volumes/&lt;external-device-5&gt;/.Spotlight-V100
8.0K	/Volumes/&lt;external-device-6&gt;/.Spotlight-V100
8.0K	/Volumes/&lt;external-device-7&gt;/.Spotlight-V100
8.0K	/Volumes/&lt;external-device-8&gt;/.Spotlight-V100
8.0K	/Volumes/&lt;external-device-9&gt;/.Spotlight-V100

A Spotlight indexes anomaly, however

sudo du -sh /.Spotlight-V100
du: /.Spotlight-V100: No such file or directory

But, that anomaly notwithstanding, I am still entirely perplexed.

WTF?

System Settings → General → Storage

Hints, suggestions and solutions more than gratefully received.

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75% of the 4TB that constitute my local, internal, storage is System Data.

background

the workaround

result

Mole.app note

And it is not Spotlight indexes gone mad

System Settings → Spotlight → Search Privacy…

Spotlight indexes

A Spotlight indexes anomaly, however

WTF?

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