Unable to save when disk space low

Recently have an issue (on all platforms) when disk space is getting low. First, once disk space gets to a critically low level I may or may not get a warning in Audacity. Usually if critically low Audacity will chop holes throughout my tracks, usually when applying an effect. After effect application will see that tracks are now chopped up with areas of silence where previously were continuous tracks. Have to be careful not to save at that point and close the affected tracks and revert back to saved version. If saved at that point will usually overwrite the saved version with the chopped up version. See images attached. In some cases, like image 2, I may be able to recover if tracks are offset where the chopped up/silent areas are by merging/rendering tracks.

The main problem I am having occurs when the disk space is low and for example, you then get a low disk space warning in Audacity. I have tried minimizing Audacity and deleting or moving files to make space. However, even though there is now space available, I cannot get the current project or any other open Audacity project to save anymore. Every time I try to save, whether to the current disk or any external drive I get errors that tracks cannot be saved. The error message will often mention some things about disk being read only or other issues.

My question is: Is there anyway to save the open projects once Audacity detects low disk space and after you have deleted/moved files and have made more space on the disk in question? Trying to save as to other disks, internal, external, sata or usb gets the error as mentioned above and files cannot be saved. I have lost a couple of important files because they could not be saved to any disk no matter how much space available on them. I have been able to save a few by exporting, either multiple track export or “mixdown” export but that does not always work as well and it too occasionally gets the error message about read-only filesystem.

Have also noted that the time it takes for Audacity to save the files seems to almost quadruple or worse when disk space is low. This includes saving to external drives when ever the main Mac drive is low on space. Have also noted that get error messages often when trying to save to FAT32 formatted USB drives. Files should be well under the FAT32 limits on individual file sizes.

It may not be complaining about that. If your system drive is in trouble, the whole world becomes unstable.

Audacity works in a system that cuts your world up into individual short chunks and then alternates between left and right. That’s one of the reasons it’s so hard to recover when a Project goes into the mud. In any one chunk, there’s no way to tell if you’re dealing with Left or Right sound.

So that picture with up and down alternating blue waves doesn’t surprise me.

Audacity also works internally at terrifically high quality. However large you think your show is, I guarantee it’s much larger than that. Each time you take an action or apply a filter or effect, Audacity saves the whole show as an UNDO. That builds up very rapidly, particularly if you’re working close to the limit.

Working at the limit all the time and sliding back and forth is Not Good. Have you ever done a drive check?

Save and close your apps and work. Restart the Mac.

Go (upper menu bar) > Utilities > Disk Utility. Select your drive > First Aid.

If it finds any serious errors, you’ll need to deal with that before you do any more production.


i check drives/ run first aid pretty regularly and generally really rarely are problems found. i have noticed that Ive probably under estimated project sizes when taking into account temp files, etc. on large multi track projects can easily get into 10’s of GB and i occassionally find that will have a final exported .wav of 1 gb or greater. typically my exported .wav mixdown files are under 100 mb at 44.1 and 32 bit float.

One of the Audacity versions (2.1.2??) defaults to saving work in /Applications. Now there’s a bad idea. I do everything on the Desktop and mop up later.

Yeah, that UNDO thing is a shock.

I use FireWire drives and I can go back and forth between them seamlessly. For a long time I ran The Mac from a FireWire drive, not the internal drive.

Jury’s out on the USB drives. They’re typically unstable or have unpredictable timing that can drive Audacity nuts. That may be one reason Audacity can’t predict well when there’s going to be a problem.

It’s still not recommended to constantly dance around overload. There was one poster who never actually saved his work. He crashed his services and depended on Audacity Disaster Recovery to repeatedly bring his show back. One day Recovery failed.


I think in my example the other day I had something like 28 GB free space on the internal Mac drive and with 3 projects open, 2 were already mixed down to a single stereo track and the other open had 10 or less tracks when started getting the low disk space error message. Was applying some edits/effects on the larger multi-track files when errors started.

Once I got the errors I went into the Mac drive and freed up to where it was showing about 60 GB free space but Audacity would not save any of the files that were already open at the time the error first popped up, Since then, I’ve already cleaned up and freed up about 100 GB now on internal Mac drive, but, does anyone know at about what amount of free space left would I start seeing error messages or start having the problems I described?

And, additionally, when you mention that when applying effects Audacity creates UNDO files of entire project, does that mean that it keeps creating new UNDO files of entire project on all subsequent apply edits/effects or does it overwrite any of previous UNDO files? I’m assuming all those UNDO files would be cleaned up when the project is closed then? and so reopening the project once saved and closed would result in much smaller size of the newly opened/previously saved projects?

And finally, temp files are not cleaned up per project? ie: temp files cleaned up for a project when it is saved and closed (even if there are other Audacity projects open?). Or only when all open Audacity projects are closed/saved are temp files cleaned up?

Mac drive and with 3 projects open, 2 were already mixed down to a single stereo track and the other open had 10 or less tracks when started getting the low disk space error message.

Ding, ding, ding! Active show management and effects, filters, etc also have to fit in memory. I think three, multi-track projects at once is loudly begging for trouble.

I’m assuming all those UNDO files would be cleaned up when the project is closed then?

Right. People are horrified that Audacity Projects do not save UNDO. That’s why we also recommend saving a uniquely-named Project every so often so you don’t have to start over if your Project goes face-first into the dirt.

only when all open Audacity projects are closed/saved are temp files cleaned up?

Darn good question. Nobody sane would try to keep multiple complex projects up in the air at the same time.


On Linux, temporary “files” are cleaned up when the project is closed, but (empty) folders may still exist if other Audacity projects are still open. Redundant temporary folders are cleaned up when the “Audacity session” (“all” open projects) closes. I imagine this is the same on Mac for Audacity 2.1.2, but may be slightly different in Audacity 2.1.3 when it is released as I hear there has been some difficulty achieving a proper clean-up with Sierra.

The bottom line is - when working with audio (or video), ensure that you have plenty of free disk space or you are likely to run into problems, whatever software you use.

@ericb7799 Please can you use the RETURN or ENTER key twice to create paragraphs? Your text is near impossible to take in when all in one huge block.


You only receive a warning of space below 100 MB on launch of Audacity or when opening a new project.

We will make an effort to fix this for release after next (2.1.4) so that Audacity will not apply an edit for which it does not have the required disk space and will warn about that.

I suspect what is happening is that you can’t save or export because the original data is now too corrupted to be read properly.

Of course, especially with magnetic drives which have to seek all over the drive to find some free clusters. This is not specific to Audacity.


The AU block files are always removed when closing the project, even in 2.1.2 on Mac. The empty folders won’t take up any significant space.


Lots of free, clean drive space is required for any real-time program. Try editing video on a cramped system.

There was the idea that Macs lean on their UNIX heritage and clean up as they go? That’s what makes UnDelete such a problem. That and the basic OS is not as succeptable to fragmenting.

But let’s not forget the poster is juggling multiple complex shows. We’re not reading an AudioBook, here.