A virus. An abrupt shutdown of the computer. A sudden ejection of the SD card. There are many ways of getting the data on your SD card corrupted.
And when that corruption extends to the file system itself, the card becomes RAW and inaccessible. But is it really a lost cause? Or can you still recover some of your data back from a RAW SD card? Let’s find out!
Pro-tip: RAW data just means uncategorized data. Your files are still there; they simply need to be processed into a usable state. So don’t use your SD card until you have recovered your data.
Don’t format the card or write any new files onto it. Doing so can erase the previous information and overwrite it with something else, after which your data is gone for good. But if you stop using the SD card immediately and move quickly, there is a good chance that you will not lose any data.
What is RAW Data
Everyone knows that a computer can only store 1s and 0s. A collection of these ‘bits’ form a byte, which accumulates to give you Kilobytes (KB), Megabytes (MB), Gigabytes (GB), and so on. But how do these bits and bytes translate to something like a picture or a document?
This is where file formats come in. Instead of storing a file in a loose sequence of unrelated numbers, the data is neatly fitted into well-defined structures. These structures contain all the information a software application needs to understand the file and process it.
For example, a BMP file holds an array of RGB pixels, storing their intensities and transparencies along with their relative positions. When an image viewer (or an image editor) accesses this file, it can easily convert these values to the picture you see on the screen.
This principle extends to all types of data. Whether it is MP3, PNG, PDF, or DOC, all file extensions are ultimately composed of purely numeric data. It is only their specified structure that allows a program to open it.
The File System
But file formats are just one part of the puzzle. Without a file system to organize these files, the OS can do nothing with them.
A typical storage disk can hold gigabytes of data. If an application had to scour through the whole storage every time it wanted to access one specific file, the file opening durations would be unbearable. Not to mention how quickly this would wear out the storage drive itself.
So a solution was devised. Each storage drive is ‘formatted’ with a file system. What a file system does is simple; it creates a table with a list of all the files present on the drive, complete with their respective sizes and memory locations.
This enables any application to find a particular file immediately, as all it needs to scan is the file table. Every time a new file is written (or an old one deleted), this file allocation table (FAT) is updated with the new information.
But what would happen if this table was to go missing?
A ‘RAW’ disk
When a storage disk does not have any file system, ie. it has not been formatted, it is considered RAW. Usually, only brand new storage media are RAW, though deleting partitions on an existing drive can also give you a RAW disk.
As the name suggests, a RAW drive contains data on a binary level, without any file system to organize it. If this has occurred on a disk that previously contained formatted files, they cannot be accessed anymore. Without the file allocation table, there is no way for the operating system to figure out where any files are or how to access them.
The only recourse offered by the OS is to format the drive. While that does solve the problem, it also removes your existing data.
Why does an SD card become RAW?
Like any other storage media, SD cards are formatted with a file system too. And when the file allocation table at the heart of this system gets affected, the files on the card can no longer be accessed by the operating system.
But how can the file system be tampered with? Here are some of the common reasons:
- 👴 In any SD card, physical deterioration and aging of the device can destroy the file system. All storage media can support a limited number of write operations, and as this limit approaches, the card starts behaving oddly. Often, the file system itself gets affected, rendering the card unusable unless formatted again.
- 🔌 This problem can also arise from an abrupt power failure. When the card suddenly loses power in the midst of reading or writing any data, the process to update the file allocation table is still ongoing. Broken off in the middle, it can render the table corrupted, and the card RAW.
- 🧲 SD cards, like all other long-term storage media, use magnetization to record data. Now, this magnetization is durable enough to last even when power has been removed from the card. But when left that way for months and years, and exposed to other magnetic fields, its internal magnetic polarities can get scrambled. This can lead to the SD card losing its file system and registering as RAW data.
- 🦠 Malware is another common source of data corruption. While it is rare for a computer virus to attack the file system itself, it can happen. And when it does, your SD card will become RAW and inaccessible to the computer.
Part 1. Perform RAW SD Card Recovery Without Formatting & Losing Data
Formatting is the easiest way of fixing a RAW SD card. The problem is that it wipes the disk clean while at it. If you want to recover your data, you should not format your SD card yet. You should run it through a good data recovery application first.
But if the OS cannot access the RAW data, how can a recovery tool do better?
How a Data Recovery Application Retrieves RAW Data
As we have discussed, a working SD card that suddenly turns RAW still has the old data on disk. It just doesn’t know where to look for it.
Data recovery software scans through the whole card, checking each and every bit of binary data. When it comes across the header of any known file type, it reads it to determine the file’s technical specifications such as its size, extension, etc. Using this information, the data recovery tool extracts the file, converting it from its binary to formatted form.
Using Disk Drill to Recover Data From a RAW SD card
While there is no dearth of SD card data recovery applications in the market, Disk Drill is probably the best in terms of both usability and efficiency. The tool gives quick and accurate results without having to install massive bloatware. It also has a permissive free plan that allows you to recover some files from a RAW SD card without having to shell a penny.
To start, download the installation file from the official site, and run the setup. Click on the Install button, or use Options to customize the install location first. The installation will be over in a few minutes.
The main window lists all the connected drives along with their sizes. Select the drive corresponding to the RAW SD card and click on the Search for lost data to start scanning.
Immediately, Disk Drill begins scanning the SD card, sorting all the recovered files by their file types. If you only want some specific files, you can Review found items to see if they have already been discovered.
When you find a file you want to recover, click on it and hit the Recover button.
Note: Don’t set the SD card itself as the destination for the recovered files, as that would overwrite the other files still being found. Instead, use a location on the computer to store the saved files.
Why Does Data Recovery Software Not Detect My SD Card?
Sometimes the problem with your SD card goes deeper than just corrupted memory or incorrect file extensions. If the issue stems from faulty or damaged hardware, it cannot be solved with a data recovery tool.
If your SD card doesn’t show up in Disk Management, there are two possibilities:
- ⭕ Zero-sized: Storage on an SD card comes in the form of memory cells. Some memory cells are lost over time; it is the natural consequence of wear and tear. But when a bulk of these cells can no longer be accessed, the SD card shows zero capacity.
- ⛔ Controller Failure: Every SD card has a built-in controller that communicates with the computer (or the mobile) when the card is slotted in. When this controller starts malfunctioning, it sends back erroneous data, misreporting the actual size of the card. This makes addressing the functioning memory cells impossible, rendering the card useless.
How to Recover Files From RAW SD Card if You Have Already Formatted Your Card?
Chances are, you used the Quick Format option. This type of formatting only creates a new file table, without trying to overwrite and reset the whole drive.
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— Chantelle ☾ (@chantellelise) September 25, 2019
In this case, your data (or at least most of it) can still be recovered. Data recovery tools like Disk Drill are quite versatile and can retrieve files even after they have been deleted or formatted. For a rundown on the complete process, refer to this guide.
Part 2. Additional Ways to Fix Your RAW SD Card
Perhaps you don’t want to install external software on your computer. Maybe you just want to give some other options a try first. Whatever your reasons, here are some existing tools that might help you fix your RAW SD card.
1. Use the Error-checking tool
This is Windows’ built-in functionality to repair file system errors. Fair warning: it is not that good. If it were, it would be the only solution you would ever need to fix a RAW drive.
That being said, it can fix small errors, so it is worth trying out. Just right-click on the drive representing your RAW SD card and head to Properties.
Switch to the Tools tab and click on the Check button. Windows will try to diagnose the file system problems and repair them. If you are lucky, that would be enough to get your SD card working again.
CHKDSK is the go-to solution for most data corruption-related problems on the computer. Unfortunately, it does not work on RAW drives.
Using the chkdsk command from CMD will only return an error message. The utility needs a file system to be present on a disk to be able to fix any bad sectors on it.
3. Assign a new drive letter
Sometimes, a malfunctioning drive starts working properly once a new drive letter is assigned. The reason behind this is that a reassignment forces the computer to mount that drive again, erasing temporary problems.
The problem is that a RAW drive is usually not a teething issue, but an actual case of missing data. Still, there is no harm in trying. To assign your SD card a new drive letter, open up Disk Management.
Right-click on the drive currently representing the card and select the Change Drive Letter and Paths option.
Click on Change.
Choose any available drive letter from the drop-down menu, and click on OK to save the changes.
4. With Diskpart
Many online guides will recommend using Diskpart, and with good reason – it works. Diskpart can make your RAW SD card accessible again. But why didn’t we mention it before? Because it is just a formatting tool.
Yes, that’s right. Diskpart is just a command-line service that can perform basic disk partitioning and formatting. As such, while it can format your SD card and remove its ‘RAW’ status, it will also remove your data. You should try some other options first (or just use a data recovery tool) before you go ahead with a format.
If you still wish to format your RAW SD card with Diskpart, here is the process.
Part 3. How to Format a RAW SD Card
If all you want is to fix the SD card itself and make it available for storage again, you just need to format it. Do keep in mind though that this will lose you all of your previous data, so only go down this route when everything of value has already been extracted from the card.
When you are ready, here are two ways of formatting your RAW SD card.
1. From the File Explorer
This is the easiest way. Just open file explorer and right-click on the drive of the SD card. In the drop-down menu that appears, select Format.
The window that appears lets you choose the file system as well as some additional options. Make sure that you are using FAT32, and enable the Quick Format option. Without it, the formatting process would overwrite all the existing data to reset it, which makes it impossible for any data to be recovered later on.
And that’s it. Click on the Start button to fire up the process.
2. From CMD
Formatting a drive can be done from the command prompt too. Doing so gives no additional advantages, so File Explorer should be the preferred option. The only reason to use the CMD is if the file explorer is not working for some reason, or if you just prefer command-line tools.
- To begin, run Command Prompt as an administrator.
- We will be using the in-built Diskpart utility for this. First, enter Diskpart to start up the tool.
- Now use the list disk command to get all the drives connected with your computer listed with their numeric ids.
- Determine which of these disks is the RAW SD card through the storage sizes alongside each entry, and take note of that number. The command select disk x (where x is the id) will choose that disk for further processing.
- All that remains is to format the disk using the format command. Specify FAT32 as the file system by typing: format fs=FAT32 and you are done.
Electronic storage can be very deceptive. Even when your computer reports an SD card to be RAW, the data might be lurking just below the surface.
The only consistent way of getting back some of that data is by using a powerful data recovery tool. Other methods like changing the drive letters or using the error checking tool seldom have any effect, unless the problem was very minor.
But with a data recovery application like Disk Drill, you can retrieve most of your data intact from a RAW SD card. Or even a formatted one if you act quickly.
A frontend developer turned writer, Levin brings his in-depth knowledge to bear in breaking down complex technical topics into a layman's perspective. A believer in emergent technologies, Levin writes about Machine Learning and Internet-of-Things to explore how people and businesses can benefit from innovation. He also likes going into the nitty-gritty details of software or hardware products to bring an unbiased review that adds value to his readers.
Andrey Vasilyev is an Editorial Advisor for Handy Recovery. Andrey is a software engineer expert with extensive expertise in data recovery, computer forensics, and data litigation. Andrey brings over 12 years of experience in software development, database administration, and hardware repair to the team.