KERNSAFE - iSCSI SAN Software and Storage Virtualization

User mode iSCSI initiator is coming for Apple silicon

Why User Mode?
Apple has steadily moved away from traditional kernel extensions and now strongly favors system extensions and user-space components. At the same time, kernel-mode solutions face significant compatibility and maintenance challenges on modern macOS, especially on Apple silicon. To provide a more sustainable path for future macOS releases and Apple silicon Macs, KernSafe is developing a new user-mode iSCSI initiator as the next step beyond the existing iSCSI Initiator X.

User Mode vs. Kernel Mode
A user-mode iSCSI initiator has a different storage model from a kernel-mode initiator. In most cases, the connected iSCSI device must be initialized and formatted with a file system that macOS can mount and manage. Unlike a kernel-mode implementation, it cannot directly expose the device to arbitrary custom file systems in the same way. This means that certain advanced use cases supported by kernel-mode storage drivers may require a different design when running entirely in user space.

A New Architecture with KCDPFS and FSKit
The new architecture is based on KernSafe’s own KCDPFS user-mode file system technology, together with Apple’s modern File System Kit (FSKit) framework. The user-mode iSCSI initiator handles iSCSI communication and storage presentation outside the kernel, while KCDPFS and FSKit provide the file-system integration needed by macOS. This architecture reduces dependence on kernel extensions and gives the product a more flexible foundation for future development.

More Features in the Future
Moving to user mode also opens the door to a broader set of capabilities. Future versions are expected to expand support for encryption, high availability and disaster recovery, Continuous Data Protection (CDP), replication, and additional storage protocols. The new architecture will allow these features to evolve more rapidly and integrate more naturally with modern macOS security and system-extension models.

Join the Beta Program
KernSafe is preparing a beta testing program for the user-mode iSCSI initiator. Beta participants may receive a free license and are encouraged to submit bug reports, compatibility information, performance results, and product suggestions. Participants who make meaningful contributions during the beta period may be granted a permanent license for continued use. Licenses provided without useful feedback or other contributions may be withdrawn in the future as the beta program evolves.

Contact KernSafe
To join the beta program, report a problem, or share your suggestions, please contact KernSafe through the KernSafe Feedback form.