Format an External Hard Drive or USB Flash Drive for Mac OS X!

Aug 11,2013 @ 20:00Hrs

If you want to insure full Mac compatibility of a new external hard drive or flash disk, you’ll want to format the drive to the Mac OS Extended filesystem. This is particularly necessary for purchases of generic PC drives, which almost always come preformatted to be Windows compatible rather than for Mac OS X.

Yes, connecting an external hard drive or USB flash key to a Mac will generally read and work fine as is because the Mac can easily read other filesystem formats, including Windows MSDOS, FAT, FAT32, ExFat, and NTFS formats, but unless you intend on using the drive between a Windows and Mac machine, formatting it to be entirely Mac compatible filesystem is highly recommended, and necessary for Time Machine and to make disks bootable.

If you have never formatted a drive before on the Mac, don’t worry, it’s super easy and we’ll walk you through the entire process.

How to Format an External Drive for Mac Compatibility

This is a simple procedure and is achieved the same way for all drive types and through all connections, be they USB, Firewire, or Thunderbolt. Formatting a drive will erase all data and partitions on the disk:

• Connect the hard drive or USB key to the Mac
• Launch Disk Utility, located in Applications > Utilities
• Locate the drive name from the left hand side of Disk Utility and click on it
• Click on the “Erase” tab across the top

















































Next to “Format:” click the contextual menu and select “Mac OS Extended (Journaled)”















Name the drive if you want, the name can be changed at any point
Click the “Erase” button and confirm again on the next pop-up window

That’s all there is to it, the drive will now format.

Smaller external hard drives, SSD’s, and USB flash keys format quickly, while a larger hard drive may take a while longer. When completed, the drive will be formatted to the Mac OS X compatible HFS+ filesystem.

Should you intend to make a OS X Mavericks USB installer or create any other bootable Mac OS X volume from a drive, or use a new drive as a fully compatible Time Machine backup drive, you will also need to complete this process.

Ref:OSXDaily

Formatting an External Device

When switching from a PC to a Mac you may find that you are unable to write files to an external hard drive you had been using with your PC. If this is the case this is because your drive is formatted with NTFS, a file system that you can only write files to with Microsoft Windows. If you want to write files to it from your Mac you will need to reformat it.

WARNING: Formatting your drive will erase all the files currently on it. Back up all of the files on the drive before erasing it.

• First you need to find and open the application Disk Utility. You can find Disk Utility in /Applications/Utilities.
• Now, find your USB drive in the list on the left hand side, and click on it, the one you want to choose is the one with its icon on the far left hand side of the colum, rather than the indented one as you can see below.

• Now, click on the 'Erase' tab.

• Opening the 'Volume Format' drop-down menu, you can see that we have quite a few options.

• From the drop down list shown above there are two sensible options to choose to format your disk.
• Choosing 'Mac OS Extended (Journaled)' (also known as HFS+) will make your drive compatible only with a Mac, and a Windows computer will not even be able to see what is on it. (unless MacDrive or another similar program is installed on the PC.)
• Choosing 'MS-DOS File System' (also known as FAT32) will make your drive completely compatible with both a Mac and Windows computer, but you cannot make a file any larger than 4GB. This is the same as formatting as FAT32 under Windows, however unlike Windows there isn't an artificial restriction which limits creating disks in FAT32 format which are bigger than 32GB.
• Whichever option you choose, you are now ready to format your drive. If you wish you can choose a new name for your hard drive, after doing that click the 'Erase' button and you will see a warning, press the 'Erase' button on the warning to continue. You will now have to wait a short time while your drive is formatted, once this is done it will appear in the Finder and you can now write files to your external hard drive from your Mac.

Ref:http://guides.macrumors.com/Image:33712Picture600.png

The best ways to format an external drive for Windows and Mac

Compare the different options for formatting an external hard drive to work with Windows and Mac. And, no: the answer isn't always FAT32.

 (Credit: Photo by Sharon Vaknin/CNET)

If you need to expand your storage space with an external hard drive and you use both Mac and PC, you'll likely run into a few obstacles. Hard drives advertised as being compatible with Windows and Mac OS may have misled you into thinking you could actually use one hard drive for both computers.

You can, but not out of the box.

Most external hard drives (HD) are sold in a format called NTFS, which is designed to work with Windows. Macs read and write to a different format, called HFS+. Another format, called FAT32 is compatible with both OS platforms. Here's a look at how the different HD format types function:

FAT32 (File Allocation Table)

- Natively read/write FAT32 on Windows and Mac OS X.

- Maximum file size: 4GB

- Maximum volume size: 2TB

NTFS (Windows NT File System)

- Natively read/write NTFS on Windows. - Read-only NTFS on Mac OS X

- Native NTFS support can be enabled in Snow Leopard and above but has proven instable.

- Maximum file size: 16 TB

- Maximum volume size: 256TB

HFS+ (Hierarchical File System, aka Mac OS Extended)

- Natively read/write HFS+ on Mac OS X

- Required for Time Machine 

- Maximum file size: 8EiB

- Maximum volume size: 8EiB

Isn't FAT32 the obvious solution?

According to the list above, formatting your hard drive to FAT32 so that you can read and write on either OS seems like the obvious solution. The video and directions below will guide you through the process, but before you format your HD to FAT32, beware of these drawbacks:

• FAT32 offers no security, unlike NTFS, which allows you to set permissions. If your HD gets into the wrong hands, that person will be able to access your data.
• The max size for any given file stored on a FAT32-formatted HD is 4GB. So, for example, if you want to store a 9GB movie, it will be impossible.
• In general, FAT32 drives are more susceptible to disk errors.
• It's not a huge issue, but FAT32 is less efficient at storing files. Its large cluster sizes waste disk space, unlike the other HD storage formats.

If you've considered these issues and would still like to use FAT32, this video will guide you through the process of formatting your HD to FAT32 using a Windows or Mac PC:....-:)

How To Format An External Hard Drive For Use With Mac And PC

How to Partition, Format External Hard Drive on Mac for Mac and Windows, How to Set Up Time Machine

OK, what are my alternatives to using FAT32?

The good news is, it's not FAT32 or nothing. The alternative solutions do require more tinkering, but if you do not want to risk FAT32's lack of security, choose from one of the following alternatives.

Option 1: Format to NTFS, and use NTFS-3G to read/write on Mac.

If you keep your hard drive's out-of-the-box NTFS format for all the reasons FAT32 displeases, there's a workaround that will allow your Mac to read and write files to the drive. NTFS-3G is an open-source program that, when coupled with MacFuse, will let you use your NTFS drive on your Mac. However, it is an open-source program, so use it at your own risk. Many have vouched for its success, but others complain about bugs.

The commercial solution, which will give you access to support and software updates, is Paragon NTFS. It's $20, offers Lion support, and you get a five-day trial to try before you buy.

Option 2: Format to HFS+, and use HFS Explorer to read/write on PC.

Conversely, you can format the HD to HFS+ and use HFSExplorer for Windows to read and write to the Mac-formatted hard drive. To get started, you'll first have to format the hard drive from NTFS to HFS+. Here's how:

• Plug your HD into the Mac and open Disk Utility, which can be accessed by searching for it in Spotlight. Then, select your hard drive from the left sidebar. Now go to the Erase tab. In the Volume Format list, select Mac OS Extended (Journaled). Then, click Erase at the bottom to format the drive. Please note that this will complete erase the drive. Any data you want to keep on that drive must be backed up elsewhere first.

Now that the hard drive is formatted to HFS+, install HFSExplorer (free) on your Windows machine to get read and write access to the drive. This is an open-source program, so use it at your own risk. Alternatively, you can opt for paid software like MacDrive instead.

Option 3: Create two partitions on your hard drive to use with each OS, separately.

This solution is a little different than the previous two because instead of having one hard drive that works with both machines, you're splitting your HD into two sections, each dedicated to a different OS. For example, if you have a 1TB hard drive, 500GB of storage can be used with your Windows computer, and 500 will be dedicated to your Mac computer.

You won't be able to write to the Mac side from your Windows computer, and vice versa, but it's a good solution for people who want all the advantages each format has to offer for its respective system. Here's how to do it:

• Step 1: Connect the empty external HD to your Mac and launch Disk Utility. Select the drive from the left sidebar, then click the Partition tab. Under Partition layout, select "2 Partitions." Now, drag the boxes to adjust the size of each partition. For example, you might want more storage for your Mac than you do for your PC.
  
  
  Now, click on the top partition, name it "Windows," and change its format to MS-DOS. Then click the second partition, name it "Mac," and change its format to Mac OS Extended (Journaled). Give your settings a final lookover and click Apply.
  
  
  Step 2: Plug the hard drive into your Windows PC. Open the Start menu and search for Disk Management. Select the search result and the Disk Management utility will launch. In the left sidebar, you should see your hard drive and its partitions. Right-click the Windows partition and select Format. In the Format dialog box, under File System, select FAT32. Click OK and complete the format process.

With these three options you'll be able to take advantage of either platform's offerings, be it Time Machine support or security options. In the end, you may end up using FAT32 for its simplicity, but don't say I didn't warn you about the risks.

How to create an OS X 10.8 Mountain Lion install drive

OS X 10.8 is only available online, but you can create your own standalone install drive for it if needed.

Apple has released its OS X 10.8 Mountain Lion (see CNET's full review) and it's available for download from the Mac App Store on systems running OS X 10.6.6 or later. If you're interested in the new OS, then be sure to read our guide on preparing your Mac for installing the upgrade, which includes information on the OS requirements, backing up, and clearing up resolvable issues before performing the upgrade.

You also might be interested in creating a standalone install drive for Mountain Lion. As with OS X Lion, Apple will likely release USB drives containing a bootable Mountain Lion installer, but this will cost you more than the App Store download. Additionally, while Apple's OS should be available using Apple's various Internet recovery options, this can often take a long time to download, especially if you do not have the fastest broadband connections available to you.

We previously outlined how to create your own OS X install drive when OS X Lion was released, and the process for Mountain Lion is for the most part the same. However, when following the procedure for Lion you might run into a snag that will prevent the drive from being created. Therefore, to create a standalone USB or optical media install drive for OS X 10.8 Mountain Lion, do this:

1. Purchase and download Lion from the Mac App Store (or use your up-to-date redemption code), and when the download is finished, the Mountain Lion installer will load. Quit the installer (press Command-Q) and go to the Application folder on your system.
   
    Locate and right-click the Mountain Lion installer to show its contents (click for larger view).
   (Credit: Screenshot by Topher Kessler/CNET)
   If you have already installed Mountain Lion, the installer will have been automatically deleted from your system. In this case, you can go to the Purchases section of the App Store and redownload the installer.
2. Right-click the "Install Mac OS X Mountain Lion" application in the Applications folder, and choose "Show package contents."
3. In the new window that opens, go to the Contents > SharedSupport folder and locate the file called "InstallESD.dmg."
4. Open Disk Utility (in the Applications > Utilities folder) and drag the InstallESD.dmg image to the device sidebar, where it should appear under your various disk and volumes listings.
5. In Disk Utility select the InstallESD.dmg file, and then you can click the Burn icon in Disk Utility's toolbar to burn the image to a DVD (single-layer 4.7GB discs do not have enough space, so use dual-layer 8.5GB discs). If you wish to create a USB or FireWire install drive instead, then continue on to step 6.
6. Connect a spare USB or FireWire drive that has at least 6GB of capacity, which should show up in Disk Utility. Optionally partition it by selecting it and using the Partition tab to split it into two logical volumes (one for the Mountain Lion installer and the other for extra storage space) by clicking the plus button to create a new partition, and then setting the first partition to be 4.8GB in size.
7. Drag the destination drive to the Destination field, and drag the InstallESD.dmg image to the Source field.
   (Credit: Screenshot by Topher Kessler/CNET) 
8. Select the InstallESD.dmg file in Disk Utility and click the Restore tab that appears in the main Disk Utility window. When you do this you should see the disk image appear in the Source field, but if not then drag it there.
9. Drag your destination drive (the desired USB or FireWire drive volume) to the Destination field, and then click the Restore button. Confirm you would like to do this, and when complete you should have a fully bootable Mountain Lion installation drive.

This process should work as described but the restoration process could fail with an error. You can overcome this by first mounting the InstallESD.dmg file and then using the mounted volume as the Source for the restoration, instead of the disk image file itself.

If restoring the InstallESD.dmg file directly does not work, then first mount it and restore the "Mac OS X Install ESD" volume that appears (click for larger view).

(Credit: Screenshot by Topher Kessler/CNET)

Related stories

• How to prepare your Mac for OS X 10.8 Mountain Lion
• AirPlay mirroring hands-on: Free Hulu on your Apple TV
• Getting started with Mountain Lion's Notification Center

To do this, first select the InstallESD.dmg file in the Disk Utility sidebar and click the Open button in the Disk Utility toolbar. When mounted, you will see a volume name appear called "Mac OS X Install ESD" underneath the image file. In the Restore tab in Disk Utility, drag this new volume to the Source field, and then repeat step 8 above to restore it to your drive of choice (special thanks to MacFixIt reader Michael A. for this tip).

When Disk Utility creates the drive in this manner, all files on it will be erased and replaced with the restored data; however, if you initially partitioned the drive (see step 6 above), then you can still use the drive's secondary volume for other purposes in addition to being a Mountain Lion install source.

Watch our hands-on First Look of Mountain Lion:

Apple - OS X Mountain Lion

Ref:CNet