TOPIC:

10.6.5.
OSX Monterey
All prefs and settings set to *in library* which is *on external SSD* at all times.
As per screenshots. All specified locations you can see there are on an external SSD.

I just got a "HD almost full" warning and then observed by internal Mac HD remaining disk space quotient reducing as a render was being done. Quite un-nerving.

I have tried searching my entire HD for internally stored FCPX render files / cache, and nothing is turning up. *All* data should be going to my external SSD where the library is.

Why is FCPX deciding to do this and how do I stop it?
(Noting FCPX already decides to mess up my office at every startup by randomizing how my workspace looks, with magical changes to my clip view size and scrolling all the way to the bottom, so I am coming to expect FCPX to just do its own thing despite settings).

Thanks...

Noting also I have conducted a system wide file search using command-shift-dot (to view hidden files) for terms "render", "cache", "final cut pro" and absolutely *zero* results are turning up. I have hunted through all of my user > library folders and went through all references to final cut pro.
I have been through all of the "documents" folders I can find, as FCPX has in the past stored libraries there. Nothing.
I have searched all of my application support folders.
What the?

It is still eating up internal HD space. It's like termites... how and why? and how do I stop it?

By "as render was being done", if you mean export was being done, FCP does not create render files for that. If render files exist, it may read those to help expedite the export but it does not create new render files during export. Rather it reads a few frames from the timeline source media (or render files if they exist), encodes that to the output codec, writes that out, goes to the next few frames, etc.

So you probably couldn't find the new render files being generated because there were none.

However, exporting is a resource-intensive process and requires a lot of memory. The early versions of Monterey had some significant memory leak problems, which would spill to the page file, consuming disk space. Make sure you are on Monterey 12.6.5.

You can run Activity Monitor and select the "Memory" tab, sort by the Memory column. Also observe the "Memory Pressure" graph at bottom. Then start your export and see how those change. If a process it taking lots of memory, that can spill to disk and consume disk space via the page file.

If your system volume does not have at least 20% free space, it does not take much activity to push it "over the edge". In that cases it's not a memory leak causing the "HD almost full" errors, just normal system activity on a disk with insufficient free space.

You can run the below terminal command before starting the export, then run it (say) every 30 sec or 60 sec during the export. This will show the space consumption of the top 2 folder levels, sorted by size. It is not instant but it should run within a few seconds. This may give some ideas about where space is being consumed. You can replace the '-d 2' argument with '-d 3', which will cause it to look 3 folder levels down. On my M1 Ultra with 1.6 TB in use on Mac HD, it takes about 14 seconds to run those.

sudo du -h -d 2 /Volumes/Macintosh\ HD/Users | sort -hr

The system can be generating swap files during the render process. The system is also generating snapshots which can be quite large. How big is the system drive and how much free space doors it have?

Just to add one more thing. The system is not very good at releasing available space like snapshots for application requests. If you're copying files to the system it will give up snapshots, but if an application starts up needing say 50 GB for an export, the system doesn't release snapshots, and the application throws a not enough space message.

There is a good article on APFS local snapshots here. Note this a MacOS management issue not an FCP bug or anomaly.

eclecticlight.co/2022/02/10/managing-sna...m-eating-free-space/

It is possible to examine the size of APFS snapshots using Disk Utility: support.apple.com/guide/disk-utility/vie...2354dc/21.0/mac/12.0

Thanks for the feedback. I had assumed there were render files being created because the available disk space number at the bottom of my Macintosh HD window was dropping, whilst the background task manager in FCPX showed "Rendering" activity. I guess it was pretty natural to assume "rendering activity" + HD space numbers dropping = render files being created on the internal HD.

It's a 1TB drive and have a lousy 50GB left in general - but again, I run all my FCPX work via external SSD - all files, all libraries, all prefs set to that SSD, always.

I'm on Monterey 12.6.1 - I'll look at upgrading to 12.6.5 once I establish upgrading won't mess up Pro Tools or anything else... thanks for the reminder, though, I really do need to do that probably.

As joema said earlier, you want/need a minimum 20% free space on your boot drive. Anything less is just asking for trouble.

Yeah, noted! Although it's curious that typically that's how it looks for me - I rarely have more than 60GB free on the internal drive - so that in itself is not the cause of the problem. But yes I understand the best practice aspect of the advice.

Absolutely the cause of the problem if you’re generating large render or export files using that system drive.

Sounds like you've been unusually lucky with your carelessness.

"Hey, be careful over there, the ice is thin!"
"I hear ya, but I haven't fallen through yet, so it must not be."
<splash!>