Have you ever inserted a memory card into your computer to copy or view a file, only to find that card inaccessible? This unfortunate situation can happen with any type of file system on memory cards, USB drives, external HDD drives, storage devices, and even internal drives. Depending on your situation, this inability to access that data can be devastating.

No matter the reason, when a partition becomes RAW, you will not able to access data on your drive and it won’t be usable until you format it. So, you have to take action to gain access to that data. One such route to success is using a data recovery tool on either macOS or Windows.

What is a RAW Partition?

Before we get into how to recover lost data, it’s important to understand what a RAW partition is. Simply stated, a RAW partition is a partition which has not been formatted with the file system recognized by the computer being used.

Memory cards and removable USB drives are constantly being inserted or attached to different machines. You might insert an SD card into one machine that reads it properly and the next computer might not understand the file system structure and breaks the partition layout, rendering that device unreadable. More often than not, you’ve simply removed that memory card or USB drive without having the operating system safely removing it first.

For example, most Windows machines use either FAT12, FAT16, FAT32, NTFS, or NTFS5 file systems. On the other hand, macOS uses APFS, HFS+, FAT32, and exFAT (with read-only support for NTFS). Linux machines use ext3, ext4, BTRFS, reiser, XFS, and more.

In some cases, it’s possible to have one system read a device formatted in another platform’s file system type. Unfortunately, this isn’t a guarantee. So when you go to read, say, an SD card formatted with the ext4 file system on a MacBook Pro, chances are good you’ll be informed the disk was not readable by the computer.

An inserted SD card was unreadable by macOS.

That Initialize option is the key. What it is informing us is that the card has not been formatted in such a way that the computer is able to read the card. You could click Initialize, however that would definitely erase all the data housed on the drive.

Is It Possible to Recover Data from a RAW Partition?

The good news is that, yes, it is possible to recover lost or inaccessible data from a RAW partition. Sometimes it’s just a matter of inserting the disk (or SD card) in question into the computer that was used to originally create the files and folders on the device. Once you’ve done that, you can copy the data to local storage, format the card to a file system the target computer understands, copy the data back, and insert the card into the target system.

recover data from a RAW partition

But what do you do when you don’t have access to that original machine (or a machine with a similar file system)? Or, what if the data was erased, the storage device was reformatted, or the data was simply damaged?

Way #1: Disk Utility

The macOS platform has a built-in tool, called Disk Utility that can sometimes detect and repair errors on your memory cards and USB drives—sometimes being the operative word. This process involves running the First Aid feature on each volume and container on the drive that contains the RAW partition, before running it on the drive itself.

Note: Make a backup of the drive where possible before attempting any fixes.

  1. Find and open Disk Utility using Finder.
  2. Click View, then Show All Devices.
  3. Select the volume in the sidebar, then click First Aid. Click Run, then follow the prompts to complete the First Aid check on the volume.
  4. Click Done when the First Aid check is finished, then repeat the same process on the container.
  5. Click Done when the First Aid check is finished, then repeat the same process on the drive.

If the Disk Utility advises the disk has been repaired, see if the partition is restored and accessible. Otherwise, refer to the Disk Utility User Guide for more information.

Way #2: TestDisk

You can recover the entire partition using TestDisk. TestDisk is an open-source recovery tool designed to restore lost or missing partitions. It’s also completely free. It doesn’t use a graphical user interface, so it can be challenging for new users. However, by following the step-by-step instructions, you can restore your missing partition in no time.

Here is a quick demonstration showing the recovery of a lost partition using TestDisk:

  1. Download and unzip TestDisk. Open testdisk_win.exe.
  2. Press Enter to create a new log file.Creating the TestDisk log file.
  3. Select the drive containing the RAW partition, then press Enter to proceed.Choosing the drive.
  4. Select the partition table type. TestDisk automatically selects the one it believes it used. Press Enter.Choosing the partition table type.
  5. Press Enter to analyze the partition structure and look for lost partitions.Analyzing the drive.
  6. Press Enter again to begin the Quick Search.Performing a quick search on the drive.
  7. When it’s done, press Enter.Selecting the discovered partition.
  8. Select the partition, then press Enter.Selecting the missing partition.
  9. If nothing appears, select Deeper Search for an in-depth search.Performing a deeper search.
  10. Select Write when the partition is found.Restoring the RAW partition.
  11. Press Y to confirm, then restart your computer once it’s finished.

If TestDisk isn’t working out for you, we’ll show you another recovery tool you can use to recover files individually further down in this article.

How to Fix a RAW Partition Without Losing Data

There are three reasons why a disk will show up as a RAW partition on storage devices:

  • The file system of the disk is not recognized by the operating system.
  • There is no file system present on the disk.
  • The file system on the drive in question is damaged.

The next question is, can a data recovery software fix RAW partitions? That depends on how bad the damage is.

  • With the drive in question inserted, open Disk Drill partition recovery software and you should see the drive ready for scanning.
  • Click the gear icon associated with the disk and click either Universal partition search or Search for lost HFS+ partition.
  • If Disk Drill is able to locate a partition, it’s possible to recover it. However, your best bet is to simply recover all of the lost files from the drive, save them to another storage device, reformat the SD card, and copy the files back.

In fact, this should also serve as a good reminder to always do regular backups of your important data. With regular backups, the chances of inaccessible data on a single data drive won’t be nearly as catastrophic.

Steps to Recover Files from a RAW Partition

Let’s take a look at the process of recovering data from an SD card in macOS, using Disk Drill. Why would you want to use this tool in particular? Although it is possible, with macOS, to recover data from a RAW partition without a third-party tool, the steps to do so require using the command line, which is a rather complicated and lengthy process.

By employing Disk Drill Partition Recovery Tool, recovering data from a RAW partition is just a few quick clicks away. And because Disk Drill includes handy features like file filters, you can quickly find the files you’re looking for. And Disk Drill adds Recovery Vault and Guaranteed Recovery data protection algorithms to the mix, something the command line cannot do for you.

Disk Drill is also capable of making a byte-to-byte backup of a failing disk, which means you can possibly salvage data from a disk that’s about to die.

To restore files from a RAW partition follow these steps:

Step 1. Download and Install Disk Drill for Windows or Mac.

Disk Drill
Data recovery for free
Your Companion for Deleted Files Recovery

Once you’ve downloaded and installed Disk Drill (the installation is just a matter of following the simple instructions), insert the unreadable SD card. Even though the card isn’t readable by the operating system, Disk Drill will see it.

Step 2. Select the RAW card in question (in this example, it’s labeled RAW) and click Search for lost data. At this point, Disk Drill will start scanning the media card to see if it can find any files.

Searching for lost data.

Step 3. Once the scan completes (depending on the size of the card, this process can take some time), click Review found items then you can begin navigating through the discovered file structure.

Marking the files for recovery.

Step 4. After selecting the files to recover, click Recover. Select where you want to store the recovered files. Make sure you’re choosing an output location on another separate physical partition.

Choose the output location.

Step 5. Click OK and the recovery process will begin. Depending on how many files you’ve selected to recover, how large those files are, and the condition of the scanned device, this can take some time. When the process completes, Disk Drill will present you with an overview screen that includes an option to jump straight to your data.

Recovery overview.

Tips to Prevent a Partition from Becoming RAW

At this point, you’re probably wondering, “How can I prevent a partition from becoming RAW?” That’s a great question. After all, you don’t want to have to go through the process of RAW partition recovery every time you insert an SD card, a USB flash drive, or an external HDD into your computer. Fortunately, there are a couple of things you can do to help prevent this from happening.

The proper way to eject a memory card in macOS.

  • The first and most important, thing you can do is never remove a USB drive or SD card without first ejecting or “Safely removing” it using your computer’s built-in function. If you simply remove the drive, without having your operating system safely unmount or eject the device, chances are good it will lead to a RAW partition.
  • Another thing you can do is make sure you always format your drives with as universal a file system as you can. Both FAT32 and NTFS file systems can be read by nearly every operating system, so those are good choices. The one problem with NTFS is that with macOS it is read-only, so your best option is always FAT32. When you opt for one of these file systems, you shouldn’t have any problem with your platform of choice needing to initialize a disk or simply not being able to read it.


It’s pretty easy to avoid having to deal with a RAW partition or drive. However, when this occasion does arise, know that you have the tools available to solve the problem. With Disk Drill your chances of recovering data from a RAW drive or partition are quite good. If you’re unsure, download the free Basic version of Disk Drill and have it scan your RAW drive or partition. If Disk Drill is able to find your inaccessible data, purchase the Pro license, and recover that data safely.


Jack Wallen

Jack Wallen is an award-winning writer for TechRepublic, ZDNet, TechTarget and Linux.com.

Read full bio
Approved by
Brett Johnson

This article has been approved by Brett Johnson, Data Recovery Engineer at ACE Data Recovery. Brett has a Bachelor's Degree in Computer Systems and Network, 12 years of experience.