Free space issue

[edrin88]

Hello everyone, new guy here. I looked for this issue before posting, but I apologize if it's a repeat.

I am trying to rip my blu-ray collection on my M1 Mac Mini w/ Big Sur. I've run into a bit of an issue. My computer has 145gb of free space on it, but according to the MakeMV program, there are only 21gbs of free space left, which is not enough to rip the movie I'm working on.

When I started (about 4 movies ago) it said I had 71gb of free space on the drive. While that was less than I knew my computer had, it still worked. It's slowly decreased to an unusable figure. If there is a cache folder, I'm unable to find it.

Any ideas?

[Billycar11]

try changing the drive / directory makemkv save the movie to and then back possibly that will make it repoll the free space and snap it out of the glitched state.
you can also try the good old uninstall and reinstall.

[dcoke22]

Figuring out how much free space you have on a modern macOS system drive is more or less impossible. Finder lies to you. When you delete a file, macOS takes that as a suggestion, even if your trash icon changes to empty.

Apple has a lot of good intentions, but all those good intentions sometimes crash into a hard reality when you're messing with large files and have relatively low amounts of 'free' disc space.

Explainer: Disk free space

Free space on an APFS volume is an illusion

Where does macOS get its volume free space figures from?

An external drive might be the easiest way to get enough free space to work on your task.

[Billycar11]

wow apple bad
why would they lie to you

[dcoke22]

wow apple bad
why would they lie to you

One of the things macOS does is something called Time Machine snapshots.

Time Machine is the macOS built-in backup software. If you plug in an external drive, you can tell macOS to keep backups on that drive and it'll start making incremental backups once an hour onto that drive. It works really well. When you reload macOS, or get a new Mac, it'll ask you If you want recovery from a Time Machine backup. Say yes and it'll pull all your data and apps from the backup.

Time Machine snapshots extends Time Machine such that if your backup disk isn't available for some reason, it'll make an incremental backup 'snapshot' into the 'free space' on your main drive. This won't help you if the drive fails, but it will help you if you accidentally delete a file and want to get it back. Getting back an accidentally deleted file is one of the most popular uses of Time Machine. That these snapshots exist in the 'free space' on your drive isn't really surfaced in the GUI anywhere (there are Terminal commands to see how many there are and how big they are). If you have a 1TB system drive and 600GB of it is used by operating system files, apps, and your data, Finder (should) say you have 400GB free. There might be 100GB used in Time Machine snapshots too, but they don't show up. In an ideal world, when the user needs to use some of the free space that is occupied by a snapshot, macOS will silently delete the oldest snapshot to make space for the user's data. But all of this stuff runs asynchronously in the background. When the amount of free space starts to get low and if the user is requesting big chunks of data at a time (like a 30GB blu-ray rip) the background processing can get behind.

There are other processes like this as well. If you have files stored in iCloud, they can also exist locally as a cached copy. They're a 'purgeable' item. Again, if the user needs the space the system could choose to get rid of locally cached copies of data stored in iCloud. Apps can also mark cache data as purgeable. The clearing of that stuff to make way for user data happens in the background in its own sweet time.

Like it or don't like it; I think Apple's intentions are good. Most users don't know about any of this stuff going on in the background and never need to know. The next level of understanding basically comes down to, don't run your system drive with low amounts of free space because things get weird.

I use a fast external drive to do all my MakeMKV things since almost none of this background stuff happens on the external drive and it is easy to have enough space.

[Billycar11]

I see
But don't see why they can't just be upfront and say oh the space is taken up file version history like it does on windows.

And this would all be a non-issue if apple let people replace the SSD instead of soldering it to the board they could just buy a 4 TB nvme for 200-250 and solve all their problems bit if they want that same about of storage from the factory well you can't apple says no one possibly needs more than 1tb in a laptop
And they charge $200 more for the 512gb to 1 TB size
Not the going rate for nand it's $0.10 a gb not the $0.40 apple is charging.

[dcoke22]

Indeed. Most people have no idea how to estimate their storage needs. And people who can make a reasonable guess will balk at the prices for 2 TB or more of storage. RAM is the same way.

My next Mac will probably be a Mac Studio. Those things start at $2000. It costs $1200 to go from the default of 512GB of storage to 4TB. It costs $400 to go from 32GB of RAM to 64GB of RAM. Those are ridiculous prices.

[Mark Alexis]

I just ran into the same issue, for the first time after some 70 rips. Disc loads, I make my rip selection, but run into the following when I hit "Make MKV": "The total size of all output files may reach as much as 73863 megabytes while there are only 68597 megabytes free on the destination drive. Do you still want to continue?"

Never seen this before. I have a 4 TB drive in my 2021 MBP, 2.19 TB of which unused. Even with MacOS' shenanigans behind the scenes this should be enough for one disc, I would assume.

Any thoughts?

[Mark Alexis]

I just ran into the same issue, for the first time after some 70 rips. Disc loads, I make my rip selection, but run into the following when I hit "Make MKV": "The total size of all output files may reach as much as 73863 megabytes while there are only 68597 megabytes free on the destination drive. Do you still want to continue?"

Never seen this before. I have a 4 TB drive in my 2021 MBP, 2.19 TB of which unused. Even with MacOS' shenanigans behind the scenes this should be enough for one disc, I would assume.

Any thoughts?

The problem remained after a reboot of my computer but then resolved itself after a second reboot. No clue why, but in any case I'm back to ripping again.

[dcoke22]

I have an external drive that I do all my MakeMKV work on. The output will eventually end up on a storage server on my network, so it is local only temporarily. Doing it on an external drive seems to minimize the effects of macOS trying to help in the background. It also lets the SSD wear caused by this work happen on easily replaceable SSDs as opposed to my Mac's internal storage.

As for having to reboot your system twice… I wonder what would've happened if you had just waited for an hour or two, leaving the computer idle? Perhaps a bunch of background processing might've been able to catch up. Either way, it is frustrating that the computer, by way of trying to be secretly helpful, becomes useless.

[Mark Alexis]

I have an external drive that I do all my MakeMKV work on. The output will eventually end up on a storage server on my network, so it is local only temporarily. Doing it on an external drive seems to minimize the effects of macOS trying to help in the background. It also lets the SSD wear caused by this work happen on easily replaceable SSDs as opposed to my Mac's internal storage.

As for having to reboot your system twice… I wonder what would've happened if you had just waited for an hour or two, leaving the computer idle? Perhaps a bunch of background processing might've been able to catch up. Either way, it is frustrating that the computer, by way of trying to be secretly helpful, becomes useless.

Good idea actually to work directly on an external drive. I'm ripping to my laptop and then transfer the MKV to my external drives.