How to Handle HFS/HFS+ Data Recovery
Just like any other file system, HFS and HFS+ drives are vulnerable to data loss due to accidental deletion, corruption, or reformatting. Fortunately, data recovery from these drives is possible with the right tools. In this article, we will show you how to use the best software to recover deleted files from HFS drives efficiently. We’ve tested these tools to verify their effectiveness in HFS data recovery, and we’ll guide you through the exact steps to restore your lost files.
What Is HFS and HFS+?
HFS (Hierarchical File System) and HFS+ are file systems developed by Apple for managing data on macOS. HFS+ replaced the original HFS, offering enhanced capabilities such as larger file size support, better handling of disk space, and improved journaling, which helps prevent data corruption. It was the default file system for Macs until APFS took over with macOS High Sierra in 2017.
Although APFS is now standard, HFS/HFS+ is still used, especially on older Macs and external hard drives. This system is particularly effective for mechanical drives, as it handles large data volumes efficiently. Recovering lost data from HFS+ systems requires recovery software that can navigate its specific architecture and retrieve data without further damage.
đź“Ś Key differences between HFS and HFS+:
- HFS+ uses a larger value to address allocation blocks than HFS, 32 bits rather than 16 bits; this means it can access 4,294,967,296 (= 232) allocation blocks rather than the 65,536 (= 216) allocation blocks available to HFS. HFS+ is optimized to manage disk space more efficiently, allowing for better performance, especially with large volumes.
- HFS+ includes journaling, which tracks changes to the file system, reducing the risk of data corruption. HFS lacks this feature, making it less reliable for protecting against unexpected crashes.
5 Common Causes of Data Loss on HFS+ Drives
Data loss on HFS/HFS+ drives occurs due to various technical issues, we list some of the most frequent causes, explained in detail:
- đź’ľ Accidental deletion. When a file is deleted on an HFS+ drive, the system doesn’t immediately erase the data. Instead, it marks the file’s space as available for new data. As long as no new data overwrites these sectors, recovery is possible. The sooner recovery is attempted, the higher the success rate, as continued use of the drive increases the risk of overwriting these blocks.
- đź—‘ Formatting the drive. Reformatting an HFS+ drive wipes out the file directory, making data inaccessible. However, since the actual data remains on the drive until overwritten, recovery software can scan the disk for data fragments. A typical HFS+ volume can hold up to 8 EB (exabytes) of data, meaning even large data sets remain recoverable as long as no significant writing occurs post-format.
- 🌌 File system corruption. Corruption often occurs due to improper ejection, power failures, or unexpected system crashes, leading to lost or inaccessible files. An unclean unmount can leave orphaned blocks or incomplete journal entries, making the drive unreadable. The journaling feature in HFS+ minimizes this risk, but if corruption occurs, the system will often fail to mount the drive. Recovery tools can access the raw data, allowing retrieval from corrupted volumes even if Disk Utility cannot repair them.
- đź› Hardware failure. Mechanical drives degrade over time, particularly in HFS+ systems that rely on traditional hard disk drives (HDDs). Disk platters can lose their magnetic alignment, reducing read/write accuracy. The average lifespan of an HDD is around 3 to 5 years, but external factors like heat or vibration can shorten this. When hardware fails, sector-level access using recovery software can sometimes extract data. In severe cases (such as read/write head failure), professional services are needed.
- 🦚 Malware attacks. While macOS is less prone to malware than other operating systems, virus attacks still occur and can delete or corrupt files on an HFS+ drive. Some malware specifically targets file systems, corrupting data at the block level. In such cases, recovery software can bypass the file system and scan the raw data to retrieve lost files.
Can You Recover Deleted Files from HFS+ Drive?
Yes, recovering deleted files from HFS/HFS+ drives is possible as long as the data hasn’t been overwritten. When a file is deleted from an HFS drive, the system does not immediately remove the file. Instead, it marks the space where the file was stored as available for new data. Until new data occupies that space, the original file remains recoverable.
How to Recover Data from HFS+ Drive Using Recovery Software
Data recovery from HFS+ drives becomes much easier with the right recovery software. Disk Drill and PhotoRec are two powerful tools that can help retrieve lost files effectively, even when the system cannot mount the drive. Let’s take a closer look.
Method 1: Disk Drill
Disk Drill is one of the most popular recovery tools available. Its powerful algorithms and simple interface make it a go-to solution for both beginners and advanced users.
Disk Drill is optimized for HFS+ recovery, whether you need to restore data from a deleted partition, recover files from a formatted drive, or retrieve files from a drive that won’t mount in Finder. As long as the drive shows up in Disk Utility, Disk Drill can access it and begin the recovery process. This makes it a versatile solution for various data loss scenarios.
Disk Drill supports hundreds of file formats, including:
- Documents (DOC, PDF, XLS, etc.)
- Images (JPG, PNG, GIF, RAW, etc.)
- Videos (MP4, MOV, AVI, etc.)
- Audio files (MP3, WAV, AAC, etc.)
- Archives (ZIP, RAR, etc.)
Follow these steps to recover your files using Disk Drill:
- Go to the official Disk Drill website and download the macOS version of the software. Install it on a different drive than the one you are recovering data from, to prevent overwriting recoverable files.
- After installation, open Disk Drill. The main interface will display a list of connected drives. Locate and select the HFS+ drive where the data was lost.
- Once the affected HFS+ drive is selected, choose the “Search for Lost Data” option. Disk Drill will perform a deep scan of the drive, looking for deleted, corrupted, or hidden files. This process may take some time depending on the size of the drive and the amount of data on it.
- After the scan completes, Disk Drill will display a list of recoverable files. You can use the filter options to narrow down the search by file type (e.g., images, documents, videos). Hover over any file and click the eye icon to preview the file and check if it is intact and recoverable.
- Select the files you want to recover by ticking the checkboxes next to their names. Click the “Recover” button. Disk Drill will prompt you to choose a recovery destination. Always save the recovered files to a different drive to avoid overwriting data on the original drive.
Method 2: PhotoRec
PhotoRec is a free, open-source tool known for its reliable recovery of various file types, including photos, documents, and videos. It operates by using a signature-based scanning method, which allows it to locate and recover files based on their unique file signatures, even if the file system is damaged or missing. Although PhotoRec does not offer the same ease of use as Disk Drill—it lacks a graphical user interface and operates through the command line—it remains a powerful and completely free solution.
Here’s how to use PhotoRec to recover your lost data:
- Download PhotoRec from its official website. The tool comes bundled with TestDisk, and you will need to extract the files to your Mac. Install it on a different drive from the one with lost data to avoid overwriting recoverable files.
- Open Terminal on your Mac. Navigate to the PhotoRec directory and type ./photorec to start the program. PhotoRec does not have a user-friendly interface like Disk Drill, so you will interact with it through text commands. Though not as intuitive, the process is still reliable for data recovery.
- Use the arrow keys to select the HFS+ drive where the data was lost. Press Enter to confirm the selection.
- Choose “Other” when prompted for the file system type.
- Choose a destination to save the recovered files. Make sure this is a different drive from the one being scanned to avoid overwriting data. PhotoRec will begin its deep scan of the HFS+ drive, locating files based on their signatures.
- After the scan finishes, PhotoRec will save the recovered files to the specified location. Unlike Disk Drill, PhotoRec doesn’t offer a preview option, so you will need to manually inspect the recovered files to verify their usability.
How to Recover a Deleted HFS+ Partition
If you’ve lost an entire HFS+ partition, TestDisk can help recover it. As we mentioned earlier, TestDisk comes bundled with PhotoRec, and while PhotoRec focuses on file recovery, TestDisk excels at restoring entire lost or deleted partitions. Even if the partition no longer appears in Finder or Disk Utility, TestDisk can still recover it. Unfortunately, like PhotoRec, TestDisk uses a command-line interface, which can be less intuitive for beginners. However, it remains a highly effective tool that we have used many times with success.
Here’s how to recover your deleted HFS+ partition using TestDisk:
- If you haven’t already, download TestDisk (bundled with PhotoRec) from its official website. Extract and install the files on a different drive to avoid overwriting any recoverable data from the affected drive.
- Open the Terminal and navigate to the directory where TestDisk is installed. Type ./testdisk and press Enter. This will launch the program in its command-line interface. While not as user-friendly as graphical tools, TestDisk is still incredibly reliable.
- When prompted, choose to create a new log file. This file records the recovery process, which can help with troubleshooting if necessary. Use the arrow keys to select the option and press Enter.
- TestDisk will display a list of connected drives. Select the drive that had the deleted HFS+ partition using the arrow keys. Confirm your selection by pressing Enter.
- TestDisk typically detects the partition table automatically. Confirm the selection and press Enter.
- Select the Analyze option, and TestDisk will scan the drive’s structure for deleted or lost partitions. Once the scan is complete, TestDisk will display a list of any found partitions, including the one that was deleted.
- If TestDisk finds the lost HFS+ partition, select it and choose the Write option. This step will restore the partition to the drive’s partition table, making it accessible again.
After TestDisk completes the recovery process, restart your Mac. Open Disk Utility to confirm the HFS+ partition has been restored. Once confirmed, back up the recovered data to prevent future loss.
How Journaling Impacts HFS+ Data Recovery Chances
The HFS+ file system uses journaling to enhance stability and protect against corruption during unexpected events like power loss. This feature logs file system changes in a journal file before they are committed to the main file system, providing consistency. While journaling helps maintain file system integrity, it also influences data recovery—both positively and negatively:
- Quick deletion and metadata loss. When a file is deleted, HFS+ updates the B-tree that tracks file metadata, which may overwrite the deleted file’s information. However, the journal file often contains a record of the file’s existence before the deletion, offering an opportunity for recovery.
- Journal-based recovery. Recovery tools can retrieve deleted files using journal data. By reading the journal’s transactional history, these tools can reconstruct recent file deletions, making recovery more precise than simple “file carving” methods.
- Limitations. The journal operates as a circular buffer, continuously overwriting older transactions. This limits the window for recovering deleted files. If significant drive activity occurs after the deletion, the journal may overwrite critical file information.
- Precision. Journaling helps recovery tools retrieve both data and metadata like filenames, allowing for more precise results.
- Limited time frame. The journal’s continuous overwriting means recovery must happen quickly before older transactions are lost.
- Partial recovery. If only some of the file’s data remains in the journal, recovery may be incomplete.
HFS+ journaling enhances file system reliability, and recovery tools can use it to recover recently deleted files with greater accuracy. However, the journal’s limited retention of data makes fast action critical for successful recovery.
Conclusion
Data recovery from HFS/HFS+ drives is possible with the right approach and quick action. The HFS+ file system’s journaling feature helps maintain stability, but it also limits the time available to recover deleted files before critical information is lost. Acting swiftly after data loss, combined with proper drive management, significantly increases the chances of successful recovery and helps protect important files from future issues.