How can I restore my partition table? Partially formatted a 1tb card with ~840gb of data on it.

Recovering a Partially Formatted CFExpress Card: A Professional Guide to Restoring Your Data

Data loss can be a distressing experience, especially when it involves valuable personal files. If you’ve accidentally formatted a storage device and suspect that your data is still recoverable, understanding the recovery process is crucial. In this article, we will explore effective methods to restore your partition table and recover your data using free, open-source tools such as TestDisk and PhotoRec.

Scenario Overview

Imagine you’ve been using a 1TB CFExpress card—specifically an Angelbird 1TB CFExpress Type B—on your RED Komodo X camera. During a routine formatting process, you mistakenly selected the wrong card, and after just about a second of initiating the format, you realized the mistake. Your Mac now prompts for a complete reformat, and the system no longer recognizes the card’s partition structure. As a result, the data appears inaccessible, though it’s likely still physically present on the drive.

Understanding the Issue

When a partition table is overwritten or lost, the data remains on the drive until it is overwritten by new data. However, the absence of a valid partition table prevents the operating system from recognizing and mounting the drive normally. The goal is to recover the original partition information so that your files can be accessed normally.

Preliminary Precautions

Avoid writing new data to the affected card to prevent overwriting potentially recoverable information.
Use a reliable card reader to connect the CFExpress card to your computer to ensure stable and fast data access.
Create a forensic image of the card if possible, especially for critical data, to prevent further damage during recovery attempts.

Tools for Recovery

Two powerful free tools frequently used in data recovery scenarios are:

TestDisk: Excellent for restoring lost partitions and repair of boot sectors.
PhotoRec: Focuses on file recovery regardless of the filesystem, ideal if the partition structure is too damaged.

Step-by-Step Recovery Process

Install and Prepare the Tools
Download TestDisk and PhotoRec from CGSecurity.
Install them on your Mac or an available Linux system for better compatibility.
Identify the Drive
Use disk management tools like diskutil list on macOS or lsblk on Linux to identify your CFExpress card’s device name (e.g., `/