macOS 27 has been out for less than a week, and it is already creating problems for anyone who depends on vendor-managed RAID storage.
Several RAID enclosure software packages have stopped functioning after upgrading to macOS 27. A Thunderbolt 3 LaCie 12Big enclosure, a staple of video editing and media storage setups, runs without issue on macOS Tahoe but breaks under the new OS. The problem sits with vendor driver and management software, not the physical enclosures themselves. With the OS only days old, the full scope of affected hardware is still unknown.
RAID arrays are the kind of setup professionals configure once and expect to leave alone. They hold project archives, raw footage, and backups. A broken management layer does not just mean the enclosure sits idle; in a worst case, it means no access to data until a vendor patch ships. These are exactly the users who cannot afford to wait on someone else's release schedule.
Apple removed its own software RAID tool from Disk Utility back in macOS Catalina, which means anyone still running third-party RAID setups in 2026 was already working around Apple's indifference. Whether vendors treat this as a priority fix or a low-volume support ticket will determine how painful the next few weeks get.