Mac OS Extended (also known as HFS Plus or HFS+) is a file system developed by Apple Inc. for use in macOS. It includes a feature called journaling, which helps protect the file system structure in the case of unexpected shutdowns like power outages. Journaling works by keeping a log of file system transactions, so the system can “replay” those transactions if needed after an improper shutdown. This helps prevent file corruption and lost data.
Windows operating systems, however, do not natively support the Mac OS Extended file system or the journaling feature. So a key question is whether Windows can still access drives formatted with Mac OS Extended (Journaled), and if any special software or drivers are required.
Compatibility Overview
In general, Macs and Windows PCs can share files and access each other’s drives without too much difficulty. This is because FAT32 formatting is universally readable by both operating systems. However, the default formatting for Mac OS is Mac OS Extended (Journaled), which is optimized for Macs.
Windows cannot natively read drives formatted this way, but solutions exist to provide compatibility. With the right software or drivers, you can access Mac OS Extended (Journaled) drives from a Windows PC.
The operating systems are designed to keep users in their respective ecosystems, but compatibility barriers can be overcome with some extra configuration.
File System Differences
The two main file systems to consider for cross-platform compatibility between Windows and Mac are HFS+ (also known as Mac OS Extended) and NTFS. HFS+ is the native file system for macOS while NTFS is the native Windows file system. There are key differences between these formats that affect how well they work across platforms.
HFS+ uses a hierarchical structured file system that is optimized for macOS. It supports features like resource forks and file-level compression natively. However, HFS+ lacks native support in Windows without third-party software. If an HFS+ formatted drive is plugged into a Windows computer, the files on the drive will not be accessible by default (Source).
In contrast, NTFS is designed by Microsoft to work with Windows. It uses more robust metadata and advanced performance features. While NTFS works seamlessly with Windows, it has limited out-of-the-box support on macOS. macOS can read NTFS drives in a read-only capacity, but cannot write to them unless special software is installed (Source).
In summary, HFS+ support on Windows requires extra software while NTFS has limited built-in Mac support. To make an external drive seamlessly accessible on both platforms, FAT32 or exFAT are better cross-platform options.
Journaling Benefits
Journaling is a file system feature that provides increased reliability and faster recovery in the event of a system crash or power failure. It works by keeping a log (or journal) of changes that will be made to the file system metadata before committing them (MiniTool).
Some key benefits of using a journaling file system include:
- Improved data integrity – The journal acts as a safeguard, ensuring file system consistency by tracking metadata changes. If the system crashes or loses power, the journal can be used to quickly replay operations and restore the file system to the last consistent state.
- Faster restart and recovery – With a journal, the system doesn’t need to scan and check the entire file system on reboot. It can simply consult the journal log to rapidly recover and restore consistency.
- Reduced disk checking time – Following an unexpected shutdown, a journaled file system only needs to replay the transactions in the log rather than scanning the full disk. This greatly reduces the time required for disk checking.
- Enhanced performance – Metadata changes are first written to the log rather than the main file system, reducing bottlenecking and fragmentation (LinkedIn).
Overall, journaling provides significant reliability improvements by protecting metadata integrity and accelerating system recovery in the event of a crash.
Journaling Limitations
While journaling file systems offer reliability and recoverability advantages, they also come with some limitations and drawbacks. One key limitation is that not all operating systems support journaling or make use of the journal data (Journaling File Systems: Benefits, Drawbacks, and Best Uses | LinkedIn). For example, Windows does not use the journal data from Mac OS Extended (HFS+) volumes. This means if a Mac OS Extended drive is corrupted, Windows will not be able to take advantage of the journal to recover files or repair the file system.
In general, the journaling process requires additional memory, disk space, and CPU utilization compared to non-journaled file systems (Journaling File System: What is It? What are the Pros and Cons? | Profolus). The journal metadata must be stored and constantly updated, which adds overhead. This can potentially impact performance, especially for write-heavy workloads.
Also, the additional fault tolerance comes at the cost of available user data storage. The space allocated to the journal reduces the total capacity available for user files on the disk. The impact depends on the implementation, but Apple recommends reserving at least 5% for HFS+ journaling.
Windows Read Capabilities
The default Windows file system NTFS cannot natively read HFS+ formatted drives, including those with journaling enabled. This is because the HFS+ file system was developed by Apple specifically for Mac operating systems. However, some versions of Windows do have limited capability to read HFS+ drives:
Windows 8 and newer versions can mount HFS+ drives as read-only. This means you can view and copy files from the HFS+ drive, but cannot write to it or modify contents without special software.
Older versions of Windows including XP, Vista, and 7 cannot recognize HFS+ formatted drives at all without third-party software. The drive will not show up in File Explorer.
No consumer versions of Windows can enable write capabilities to HFS+ without additional software drivers. This write-protection is to prevent corruption of the HFS+ file system from improper writes. For full read/write access, third-party HFS+ drivers need to be installed on Windows.
Overall, all Windows versions have very limited native capability to read HFS+ formatted drives. Read-only access is available in Windows 8 and newer, while older Windows versions can’t read HFS+ at all without help from third-party software. To enable full access including writes, specialized drivers are required on any Windows version.
(Sources: https://www.reddit.com/r/techsupport/comments/ch3fhv/how_to_read_mac_os_extended_journaled_on_windows/, https://iboysoft.com/wiki/mac-os-extended-journaled.html)
Using Third-Party Drivers
While Windows does not natively support reading and writing to HFS+ drives, third-party drivers can add this capability. Popular options include HFS+ for Windows by Paragon Software and the open-source HFSPlus driver.
These HFS+ drivers allow Windows to recognize HFS+ drives and directly access the files stored on them. Paragon HFS+ for Windows provides a friendly user interface for exploring and managing HFS+ volumes. It installs as a regular Windows service for full transparency.
Using a third-party HFS+ driver eliminates the need to reformat the drive to a file system like exFAT that Windows understands. Drivers like Paragon HFS+ also support journaling and other HFS+ specific features not available in other file systems.
With the driver installed, HFS+ drives can be accessed on Windows similarly to a native NTFS or FAT32 drive. Files can be viewed, edited, copied, moved, and otherwise managed. This improves compatibility without compromising the original file system.
Accessing Files
Windows includes built-in read-only support for HFS+ drives, allowing you to access Mac-formatted volumes in read-only mode. To enable this, follow these steps:
- Connect the Mac-formatted drive to your Windows PC via USB, Thunderbolt, or another interface.
- Open File Explorer and navigate to This PC. The Mac volume will appear with the drive label.
- Double click on the volume to open it and view the files. However, you will not be able to edit, delete, move, or make changes to the files.
While built-in Windows support provides read access, you cannot write to HFS+ drives without third-party software. Options like HFSExplorer or Paragon HFS+ allow full read/write access to HFS+ volumes on Windows.
HFSExplorer is a free, open-source utility that enables read/write support. After installing, right-click on the mounted Mac volume in File Explorer and select “Load File System” in HFSExplorer to gain full access. Paragon HFS+ is a paid driver that similarly unlocks read/write abilities.
Using one of these third-party options is recommended for modifying files, transferring data, or fully utilizing a Mac-formatted drive from your Windows PC.
Conversion Option
If you need to use your Mac-formatted drive regularly with Windows computers, you may want to convert it to a Windows-friendly format like exFAT or FAT32. This can be done non-destructively in Disk Utility on Mac. Simply connect the drive, launch Disk Utility, select the drive, click “Erase”, then choose “exFAT” or “MS-DOS (FAT)” as the format. Be aware this will erase all data currently on the drive, so you’ll want to back up your data first. Converting to a Windows format will allow the drive to be fully readable and writable on both Mac and Windows without any additional software. According to Apple’s support document here, exFAT has broader compatibility with Windows and Mac.
Summary
In summary, Windows by default cannot natively read files on a Mac OS Extended (HFS Plus) drive using journaling due to compatibility issues between the Windows NTFS file system and Mac’s HFS Plus system. However, third-party software drivers can enable Windows to read HFS Plus drives. The best solution for accessing Mac files on Windows is to copy the files to a native Windows drive or use a file format both operating systems support. Converting the drive from HFS Plus to a Windows-compatible format will also allow access, but at the cost of losing the benefits of file journaling. To directly answer the initial question – Windows cannot read a Mac OS Extended journaled drive without help from additional software.
