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Published on October 20th, 2013
Now your external drive has been formatted to be fully compatible with Apple MacOS, and you can edit, read, and write files to it as you want. How to Partition an External Hard Drive on Mac. If you want to create multiple partitions on your external hard drive (in fact, you should for better file organization), here’s a step-by-step guide. Click the icon for your external hard drive in the sidebar on the left. Click the Erase tab along the top of the window. From the Volume Format menu, choose Mac OS Extended (Journaled). Enter a name for the external hard drive in the Name field.
How to properly Format/Reformat a hard drive for Mac OS
A hard drive or hard disk can be used in any type of computer, whether for PC (Windows) or for Mac. Before you can use it though, you need to properly format or reformat a hard drive so that it will become compatible or readable with the Operating System that you are using. In this guide I will show you how you can properly format/reformat a hard drive for Mac OS. Formatting a hard drive for Windows will be discussed in another article.
Formatting and Reformatting a hard drive or hard disk is an easy task (if you know how). But it is also dangerous as it can result in loosing data or corrupting the drive when it is not done properly.
Before I proceed, I will be explaining some few things regarding formatting a hard drive. But if you want to know the instructions in formatting and reformatting a hard drive, just scroll down to the instructions below.
First, why do we need to format and/or reformat a hard drive. I will name some reasons, common reasons why we need to do this.
1. Some hard drives are already pre-formatted for a certain platform or system, like when you buy it out of the box it’s already formatted for Mac or Windows. But when it is not, we need to format the drive.
2. Hard drives are formatted so that a particular platform or operating system will be able to read and recognize the drive, whether it is an internal drive or external drive.
3. Hard drives are reformatted because sometimes we need to do clean up and we just want to wipe everything out that is written in the drive.
4. Formatting/Reformatting a drive can also remove soft bad sectors. But not necessarily always. Sometimes when a drive has a physical bad sector, reformatting it could spread the damage.
5. We reformat a hard drive if we are switching from one platform to another (Windows to Mac and vice verse)
Back to the main topic, below is a step by step instruction on how to Format/Reformat a hard drive for Mac OS.
Warning: FORMATTING and REFORMATTING A DRIVE ERASES EVERYTHING. Proceed with caution. Do backup your files first.
Formatting/Reformatting a hard drive for a Mac
1. Open Disk Utility by clicking Finder -> Applications -> Utilities and finally click Disk Utility.
2. Choose the hard drive that you want to format or reformat. Make sure that it is the correct hard drive!
3. Go to the Partition Tab
4. Click the Current Volume Scheme drop down menu and choose One (1) partition.
5. Click Options, and from the Partition Scheme provided choose “GUID Partition Table” radio button or “Apple Partition Map” radio button.
6. Then click OK. Then key-in in the other options like Volume Name, Format and Size.
In this juncture, in the Format option, choose Mac OS for Mac OS X. Or MS-DOS File System otherwise.
In this juncture, in the Format option, choose Mac OS for Mac OS X. Or MS-DOS File System otherwise.
7. Click Apply and the Partition Disk screen will open.
8. Click Partition. During this time the drive or volume will dismount and it will be partitioned and formatted. DO NOT TURN OFF OR RESTART your computer during this time!
Time Machine may pop up asking you to use the newly formatted drive for backups. Just cancel it to proceed.
9. After that, just exit Disk Utility and your done!
Hope this “format/reformat a hard drive for Mac” guide helped!
Below are some recommended Internal Hard drive and External Hard Drives that you might like. All of them are best sellers.
Currently Best Selling Internal Hard Drives
1. WD Blue 1 TB Desktop Hard Drive: 3.5 Inch, 7200 RPM, SATA 6 Gb/s, 64 MB Cache – WD10EZEX
2. WD Red 3 TB NAS Hard Drive: 3.5 Inch, SATA III, 64 MB Cache – WD30EFRX
3. Western Digital WD1002FAEX Caviar Black 1 TB SATA III 7200 RPM 64 MB Cache Internal Desktop 3.5″ Hard Drive
4. Seagate Barracuda 3 TB HDD SATA 6 Gb/s NCQ 64MB Cache 7200 RPM 3.5-Inch Internal Bare Drive ST3000DM001
5. Western Digital 4 TB WD Green SATA III 5400 RPM 64 MB Cache Bulk/OEM Desktop Hard Drive WD40EZRX
Currently Best Selling External Hard Drives
1. WD My Passport Ultra Portable External Hard Drive USB 3.0 with Auto and Cloud Backup
2. WD My Cloud Personal Cloud Storage
3. WD My Passport Portable External Hard Drive Storage USB 3.0
4. WD My Passport for Mac Portable External Hard Drive Storage USB 3.0
5. Seagate Backup Plus USB 3.0 Desktop External Hard Drive
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So, you just bought an external hard drive or a portable SSD and wanted to use it on your Mac. But somehow, macOS doesn’t allow you to write data to the drive.
That’s all because it’s been initialized with Windows NT File System (NTFS), which is primarily for PCs. Apple Mac machines support a different file system.
In this post, I’m going to show you how to format your external drive for a Mac compatible file system i.e. Mac OS Extended (Journaled). Just follow this easy step-by-step guide and you’re all set.
Important note: If you have useful files stored on the external drive, be sure to copy or transfer them to another safe place prior to formatting. The operation will erase all data and your files will be gone for good. You could use a recovery program like Data Rescue to retrieve them, but the odds of recovery vary.
Pro tip: If your external drive has a large volume, like mine – a 2TB Seagate Expansion. I highly recommend you also create multiple partitions. I’ll also show you how to do that below.
Most External Hard Drives Are Initiated with NTFS
During the last several years, I’ve used several removable drives, including a 500GB WD My Passport, 32GB Lexar flash drive, and a few others.
Three weeks ago, I bought a brand new 2TB Seagate Expansion to backup my MacBook Pro before I updated to the latest macOS, 10.13 High Sierra (also see those High Sierra issues I encountered).
When I connected the Seagate to my Mac, the drive icon showed up like this.
When I opened it, the default content was all there. Since I wanted to use it on Mac, I clicked the blue logo with the text “Start_Here-Mac”.
It brought me to a webpage on Seagate’s site, where it clearly indicated the drive was initially set up to work with a Windows PC. If I wanted to use it with Mac OS or Time Machine backup (which is my intent), I’ll need to format the drive for my Mac.
I then right-clicked the external drive icon on Mac desktop > Get Info. It showed this format:
Format: Windows NT File System (NTFS)
What is NTFS? I’m not going to explain here; you can read more on Wikipedia. The problem is that on macOS, you can’t work with files saved on an NTFS drive unless you use a paid app Paragon NTFS for Mac.
How to Format an External Drive to Work with Mac (from NTFS to Mac OS Extended)?
Note: The tutorial and screenshots below are based on macOS Sierra 10.12.5. They might be different if your Mac has a different version.
Step 1: Open Disk Utility.
The quickest way to do this is a simple Spotlight search (click the search icon on the upper right corner), or go to Applications > Utilities > Disk Utility.
Step 2: Highlight your external drive and click “Erase”.
Make sure your drive is connected. It should show up on the left panel under “External”. Select that disk and click the “Erase” button, the one highlighted in red in the screenshot below.
Step 3: Select “Mac OS Extended (Journaled)” in Format.
A new window will pop up asking which file system you’d like to format the external drive to. By default, it’s the Windows NT File System (NTFS). Select the one shown below.
Pro tip: If you want to use the external drive for both Mac and PC, you can also select “ExFAT”. Learn more about the differences between these file systems from this thread.
By the way, you can also rename your external drive.
Step 4: Wait until the erasing process is complete.
For me, it took less than a minute to format my 2TB Seagate Expansion.
You can also check to see if the format was successful. Right-click on the icon for your external drive on Mac desktop, then select “Get Info”. Under “Format”, you should see text like this:
Congratulations! Now your external drive has been formatted to be fully compatible with Apple MacOS, and you can edit, read, and write files to it as you want.
How to Partition an External Hard Drive on Mac
If you want to create multiple partitions on your external hard drive (in fact, you should for better file organization), here’s a step-by-step guide:
Step 1: Highlight your drive and click “Partition” in Disk Utility.
Open the Disk Utility app and highlight your external hard drive. Make sure you select the disk icon right under “External”. If you select the one below it, the Partition option will be greyed out and become unclickable.
Step 2: Add partitions and allocate volume for each one.
After clicking “Partition”, you’ll see this window. Located on the left is a big blue circle with the name of your external drive together with its volume size. What you need to do next is click the add “+” button to increase the number of partitions on your external disk. Then allocate the desired volume to each partition. You can do that by clicking the small white circle and dragging it around.
After that, you can rename each partition and define a file system for it.
Step 3: Confirm your operation.
Once you hit “Apply”, a new window pops up asking for your confirmation. Take a few seconds to read the text description to make sure it reflects what you intend to do, then click the “Partition” button to continue.
Step 4: Wait until it says “Operation successful.”
To check whether the operation is really successful, go to your Mac desktop. You should see multiple disk icons show up. I chose to create two partitions on my Seagate Expansion — one for backup, the other for personal use. You can find more info in this post: How to Backup Mac to an External Hard Drive.
That wraps up this tutorial article. I hope you find it helpful. As always, let me know if you have any issues during the formatting or partitioning process.