There’s just one last bit of information you need to know to erase the free space on a hard drive from the command line. In Unix, all devices appear as part of the file system tree, and in macOS. OS X Disk Utility missing options to erase free disk space. If you have purchased a new Mac or have upgraded your hard drive on an older Mac, you may find when accessing the option to erase free. Answer: A: I had the same problem as well. I went to system preferences and turned off FileVault under security and privacy. Then I restarted my mac in recovery mode, OS X: About OS X Recovery - Apple Support. Selected my mac drive and the partition tab and I was able to resize my main drive.

1. How To Free Up Space On Mac
2. What Does Erase Free Space On Mac Mean
3. Erase Empty Space
4. Free Space On A Mac

Sep 08, 2021 • Filed to: Solve Mac Problems • Proven solutions

Every time you delete any file or document on the Mac hard drive it creates free space. This free space can be utilized for storing other data. However, if this free space doesn’t get overwritten, then it can be used to retrieve the previous data that it held using a data recovery tool. Now, if you are selling the hard drive of your Mac and don’t want the person buying it to recover the documents that you deleted then you must erase free space on Mac hard drive. However, make sure that the erasure is done securely without damaging the hard disk.

Part 1: How to Erase Free Space on Hard Drives in Mac OS X

You will have to use the Disk Utility app provided by your Mac OS X toerase free space on Mac hard drive. It offers you the chance to overwrite on the free space left on your hard disk so that no one can retrieve the data that was previously stored on it. However, do keep in mind that this method for free space erasure is only applicable for traditional hard drive and won’t work on SSD versions that utilize flash memory.

1. The initial step is to start the Disk Utility app. This app is located in the utility menu which can itself be found in the Applications menu. You can use the Launchpad for launching this app as well.
2. If the hard drive whose free spaces you want to erase is an external hard disk then you would have to connect it to the Mac and then select it from the menu located on the left-hand side of the screen.
3. Click the Erase free space button after opening the Erase tab.
4. Pick the level of erasure you want and then click the Erase free space to start the overwriting process on the hard drive’s vacant spaces.

1. There are three different erasure options available to you which are Fastest, Secure, and Most Secure. Fastest option overwrites the free space just once while Secure and Most Secure options do that three and seven times respectively.
2. Select any of the erasure options that you like and then click the Erase free space button.

Part 2: How to Secure Erase Free Space on Hard Drives in Windows

Although the Disk Utility app of Mac OS X can erase free space on Mac hard drive, there is a chance that it might not be able to do so in a secure manner. To make sure that the erasing of the free space is completed without any damage to the hard drive then using a data erasure tool is the best option. There are various such tools available on the internet but the best one among them isStellar BitRaser for File. It can secure erase free space on hard drives and ensure that the deleted data can’t be recovered.

• Completely erases the data, ensuring that it can’t be recovered using any data recovery tool.
• Supports multiple data erase algorithms that can be used for erasing data.
• Provides a search feature for quickly search the file or document which needs to be erased from the hard drive.
• Offers the chance to erase the chat history of messaging services like Yahoo and Skype.
• Capable of erasing all traces of internet activity including the internet history maintained by popularly used browsers.

Step 1: Download Stellar BitRaser for File on your Windows PC, take out the hard drive on Mac, and connect it to Windows computer.

Step 2: Click the 'Erase Unused Space' option on the left, to select your Mac hard drive.

Step 3: Selected your Mac hard drive and click the 'Erase Now' button to process.

Step 4: After a while, the Mac hard drive erase complete and you can reboot the system.

While other data erasure tools take several passes to erase the free space on a hard drive, Stellar BitRaser only requires a single pass to erase it permanently. However, if you feel the need to take another pass then you can take two more passes. This will ensure beyond doubt that the free space on your Mac hard drive is erased forever.

For you to use Stellar BitRaser for File to erase free space on Mac hard drive, you need to take it out from your Mac first. The reason for this is that this data erasure tool isn’t compatible with Mac OS X and works only on Windows. So, you need to connect the Mac hard disk to a Windows PC before you erase the free spaces on it using Stellar BitRaser for File.

In short, deleting data on the Mac hard drive doesn’t securely erase it. It just creates free space that can be used for recovering the deleted data using a data recovery tool. So, you need to erase free space on Mac hard drive. The Disk Utility app of Mac OS X can be used for the erasure of these free spaces. However, for secure erasure, you need to make use of a reliable data erasure tool like Stellar BitRaser for File. It can erase the vacant spaces on your Mac hard drive and make sure that the data that they contained previously can’t be retrieved using anyprofessional Mac data recovery tool.

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If you regularly work in programs like Adobe Premiere Pro, Final Cut Pro, and Adobe Photoshop, you’ve probably encountered errors relating to a 'scratch disk.' The most common error is Photoshop’s refusal to open, along with the message 'Could not initialize Photoshop because the scratch disks are full.'

If you’ve stumbled on this page because you’ve experienced this issue, you’re in luck: we’re going to show you how to resolve your scratch disk problem easily and, as a bonus, keep your computer clean and performing at its best.

What is a scratch disk?

Before we highlight some solutions, it would be a good idea to have at least a general sense of what a scratch disk actually is. When you are using programs like Photoshop or Final Cut Pro, they require a working space called virtual memory or cache memory. This is where temporary project files are stored and accessed.

For this guide, we are focusing our laser sights on Photoshop. After all, it is the most common application. But rest assured that the info we cover will apply to most programs that rely on scratch drives.

Scratch disk is your hard drive space used by Photoshop as virtual memory when there is not enough RAM to complete a task. Photoshop allows you to assign several scratch disks: that way, it has more space at its disposal.

When working with large images and lots of layers, Photoshop is secretly chewing up your drive space by rapidly creating a mountain of project temp files.

It’s important to note that when you set up Photoshop, you will have the option to assign the scratch disks to the drive of your choice. We highly recommend not using your system drive unless you have no other alternatives.

Reasons behind “scratch disks are full” error

Temporary files are the most significant reason behind the “scratch disks are full” error. They usually mass up in your drive without leaving single evidence of their presence. If you have a habit of force-quitting Photoshop, you may have a lot of temporary files stored in your system. As Photoshop can’t fully close all projects after you quitted it so rapidly, it keeps such files on your machine.

Here are some other reasons that may cause the mentioned message:

• Lack of space in the drive where the scratch disk is located
• The partition of the disk being used by Photoshop is full
• Limited RAM allowed for the Photoshop

What to do when your scratch disks are full?

How To Free Up Space On Mac

Next, we’ll explain how to clear out the scratch disk and fix the Photoshop issue on a Mac. If you’ve faced a problem on the Windows computer, follow the instructions below.

How to fix “scratch disks are full” error on Mac

Mac users receive a 'scratch disk full' message when Photoshop (or any of the other programs) has used up all the space on the hard drive that has been assigned as a scratch disk. This used-up space is temporary and separate from your actual project file.

The problem is that Photoshop doesn't always get rid of these temporary files when they aren't needed anymore, which is more like a permanent problem if the user can't find a solution.

So how to clear your scratch disks? Let's find out.

Important takeout: If your HD is full, Photoshop will display scratch disk errors.

1. Clear your Photoshop cache

Photoshop has an in-built solution for deleting specific Photoshop caches. When these pesky caches aren’t removed automatically by the program, they can grow and take up a lot of space on your scratch disk.

To use this tool, simply enter Photoshop in Mac and with an image open:

• Click the Edit menu button.
• Hover your mouse over 'purge' to reveal 4 different options.
• Undo, Clipboard, Histories, All. If an item is greyed out, that means it has already been deleted.
• Select the specific item you want to delete or select 'all' to delete all of your caches.
• You will be warned that the purge cannot be undone, so make sure you don’t need a previous version of one of your projects and then click OK.

A good way to keep Photoshop cache from piling up is by running regular disk cleanups. But here is a problem: the cache sits so deep in system folders (and their subfolders) that deleting it manually becomes a pain. A company called MacPaw produced a tool just for this purpose, CleanMyMac X. You've heard of similar tools, but that one actually pioneered Mac cleanup.

Here’s how you can schedule regular cleanings with CleanMyMac X:

1. Launch CleanMyMac X tool.
2. Click System Junk and press Scan.
3. Click Review Details to deselect the data you want to keep.
4. Hit Clean to clean up junk files.

Just let it do its thing. That way, you’ll never forget to clear Photoshop cache and tons of other system junk on your system.

You can download CleanMyMac X free version and see how it works.

How your Scratch drive is filling up, an example from Sketch

Along with Photoshop, Sketch is another app that keeps temporary versions of projects on your disk. And it eats up a whole lot: from 60 to 220 GB on average.

Each time you press Command + S, some space is wasted away from your Scratch drive. Say your file weighs 23 MB. Then, 7 temporary editions would increase that size to 161 MB. This problem hasn’t been widely known until recently, but, luckily, there is an automatic solution.

CleanMyMac’s System Junk module lists Documents’ Versions from Sketch and other similar apps. You can keep the final and the oldest version of a project and delete all revisions in-between. Voila, you’ve got free space again!

2. Delete your temp files

When it comes to wasting space on your scratch disk, the worst culprit is often Photoshop's own temp files. If Photoshop isn't going to get rid of them, I guess you’re going to have to do the job yourself.

To find them, you'll need to look for files that begin with 'pst' and then a string of numbers followed by the file extension '.tmp.' Search 'Photoshop Temp' with a space between the two words.

You can just search your scratch drive, but to make sure everything is found, rather perform the search on the entire computer. It may take a couple of minutes for the search to complete, so pop into the kitchen for a quick snack while you wait.

When you return, you should have a long list of files. If your work is saved and the program is closed, you can safely delete these files and watch as your scratch disk space is reclaimed.

3. Clear your disk space

If you don't have another drive or don't want to buy one, then it's time to do some spring cleaning. Look at the drive contents to see if you can delete anything you don't need. Is there storage space that can be cleared? Usually, there is, so go ahead and delete your old files and free up some space.

Alternatively, you can simply transfer files to external drives, DVDs, or cloud storage solutions like Dropbox and iCloud.

Take a look at our How to Clean Your Startup Disk (10 Ways). Inside we have lots of practical advice for macOS users who want a clean drive that performs well. Even if your scratch disk isn’t your startup drive, and we hope that is the case, there are many tips to help you spring clean like a pro.

Notice for macOS Sierra (and higher) users:Users of macOS Sierra might be aware that Apple has added new tools to 'help' manage storage space. If you navigate to Apple Menu > About This Mac > Storage tab, you will see the new Sierra bar graph.

If you click on 'manage,' you will be taken to the new tools. While there are some truly helpful elements, like using Optimized Storage to customize what email attachments download to your Mac, most of the tools move junk from one place to another place.

Because many of these processes are automatic, Sierra users might not be aware of what the OS is doing on their behalf. If it sounds like a good idea to have macOS deciding what files to send to iCloud and what iTunes videos to remove, go for it.

For everyone else, we’d recommend turning off these tools or at least making sure you understand them fully before turning them on.

What Does Erase Free Space On Mac Mean

It can be challenging to check and analyze all contents of your disk space. Luckily, some tools can provide a disk scan and can save up lots of space on your Mac. Apps notarized by Apple are best for this job. CleanMyMac X, the app I talked about earlier, has a Large & Old Files feature, which finds and removes massive files stored on your Mac.

4. Change your scratch disk

If the disk being used is nearly full, change the directory for a more spacious one. Then, restart Photoshop. You can change the Scratch Disk location by pressing the Command + Option when launching Photoshop. It can be a hassle, but if you keep an eye on the available space on your scratch disk, you can do something when space is becoming limited. It’s also worth noting that problems don't just occur when the drive is completely full, hard drives should ideally never be above 85% capacity. Pass that threshold, and problems will be just around the corner.

So, you've identified rapidly depleting free space on your Mac hard drive — now what? Well, it may be a good idea to change your scratch disk to another drive in your system (just not the system drive, as that is one drive you really don't want to slow down). If you don't have another drive, you could purchase one, with SSD being the best option for Mac OS X scratch disk purposes.

Follow these steps to change your scratch disk in Photoshop:

1. Click on the Photoshop menu.
2. Go to Preferences and then Scratch Disk.
3. Tick the checkbox to select or remove a drive as the scratch disk.
4. Click OK.
5. Restart Photoshop.

You can change the Scratch Disk location by pressing Command + Option when launching Photoshop.

5. Consider buying a new SSD

The scratch disk problem happens because of 2 simple reasons: lack of RAM and lack of HDD space. Both can be addressed if you buy a Thunderbolt SSD (solid-state drive) to use as your Scratch Disk. By today’s standards, 60 GBs should be enough.

Buy an external SSD to use as a Scratch Disk. 60 GB should be enough.

6. Follow the 15% rule

Not strictly a rule, but rather a common practice states that you should keep at least 10-15% of your disk space free at all times. If your HDD size is 256 GB, your lower limit is 25 GB. You’ll have enough room to render your Photoshop files, save multiple project copies, etc.

Loud fans noise is a sign your CPU is overloaded and approaching its carrying capacity.

7. Free up RAM in Terminal

When Photoshop gets paralyzed due to lack of RAM, there is a command you can run in Terminal.

1. Open the Terminal app (find it in the Launchpad).
2. Paste in: sudo purge
3. Then, enter your password.

At first, you may not see the difference, but you’ve just flushed your RAM, releasing all the files kept in virtual memory. There are a few more ways to free up RAM; check them out too.

You can also download CleanMyMac (get a free edition here) and use its Free UP RAM command.

1. Install the app and click on Maintenance.
2. Select Free Up RAM and click Run.

You can apply this trick anytime to unfreeze an app. Also, check out the other tools in the Maintenance section. They will help you take some load off your Mac’s memory.

8. Search for hidden files in your Photoshop folder

Erase Empty Space

Some projects’ leftovers are invisible and yet take up lots of space. There is a shortcut combination to display hidden files in whatever folder you are in. So, open your main Photoshop folder and press Command + Shift + Period. If you find any greyed-out folders, check their weight.

To see hidden files in any folder, press Command+Shift+Period.

As you see, there are many methods to solve the “scratch disks are full” error. There is also one more way to reorganize data on your Mac and save up some space. Disk defragmentation gathers related items and lets you delete unneeded data as well as leftovers. Note that the latest macOS doesn’t need to be defragmented as Apple has provided it with in-built utilities, which automatically remove fragmented files. So, defragmentation may only work for you if your Mac’s running the OS version earlier than OS X 10.2.

How to clear the scratch disk on Windows

If you are experiencing a “scratch disks are full” error on your Windows computer, freeing up space in the drive that accommodates the scratch disk may fix the problem. To do that, you need first to find out which drive Photoshop uses as a scratch disk.

1. Open Photoshop and go to Edit > Preferences.
2. Choose Scratch Disks.
3. Check which drive is used as a scratch disk.

The scratch disk should have at least 40GB of free space. If you see that it’s running out of space, access the drive and remove or transfer the largest files.

Another thing you may do to fix the error is clear out Photoshop temporary files. Just make sure you save your work first and close all Adobe apps. Then, go to the temp data folder
C:UsersYour UsernameAppDataLocalTemp. Look for the files that have “Photoshop Temp” in their names, highlight and remove them.

Free Space On A Mac

The 'Scratch Disk Is Full' error is fixed!

If you followed this guide, there is absolutely no reason why you should ever have to deal with the annoying 'scratch disk full' error again. Next time you want to create something amazing in Photoshop, you should experience something new - a Photoshop that runs so smoothly it practically purrs.

Whether you solve the problem yourself or let a great piece of software like CleanMyMac X do it for you, just make sure you clean up your scratch disk. Your Mac will thank you for it*.

*Not literally. That would be weird.

Frequently asked questions

Why does the “scratch disks are full” error may appear?

The number one reason for the “scratch disks are full” message is the lack of space in the drive where scratch disks are located. You can also run out of space in the partition of the disk allocated for Photoshop, which may also cause the above-mentioned error.

What are Photoshop temporary files?

Temporary files will appear if you don’t close Photoshop fully or open the Smart Object and don’t close them with the Smart Object layer. Photoshop temp files have a '.tmp' extension, so it’s easy to find them on your Mac.

How to fix the “scratch disks are full” issue?

One of the solutions is to change the scratch disk allocation. You may also need to clear the Photoshop cache and remove temporary files.