Apple’s AFP will no longer be the default file sharing protocol in OS X 10.9 “Mavericks.” Apple is adding Microsoft’s SMB2 to OS X and making it the default for file sharing with Windows — and with Macs running OS X 10.9 as well. SMB will still be supported for compatibility with older PCs and devices, and AFP will be supported for file sharing with previous OS X versions.
Apple’s adoption of SMB2 (Server Message Block 2), which Microsoft rolled out in Windows Vista, could improve file sharing with Windows servers and PCs. Apple’s SMB implementations have been prone to problems for since OS X 10.4 Tiger (for instance, see here and here). With Lion, Apple abandoned the SMB code it had been using, which was based on Samba from Linux, and wrote its own SMB code for OS X. Although it improved file sharing with Windows, it didn’t make file sharing as trouble-free as it is between Macs.
Unlike SMB, AFP (short for Apple File Protocol), the default Mac file sharing protocol since Apple enabled network file sharing in the 1980’s, has always been the most reliable and trouble-free way to share files on Macs. The notable exception was with the release of OS X 10.7 Lion, when Apple turned off older authentication methods, affecting some older network attached storage devices and legacy servers. (There are workarounds to that problem.)
Apple states that OS X Mavericks will automatically default to using SMB2 when accessing shares on other OS X Mavericks Macs. PCs running Windows Vista, Windows 7, and Windows will be connected to an OS X Mavericks Mac using SMB2. When a Mac running Mountain Lion or earlier tries to connect, OS X Mavericks will use AFP. Mavericks will also need AFP to connect to many network-attached storage devices — including Apple’s own Time Capsule. (Apple’s new AirPort Time Capsule, introduced on Monday, may support SMB2, but Apple doesn’t list supported file sharing standards in the product page or it the product manual.) OS X 10.9 Mavericks will also retain the older SMB standard for accessing Windows XP and older servers and devices.
Apple says that SMB2 will also make file sharing faster with both Windows and Macs running OS X Mavericks. From Apple’s Mavericks Core Technology document released on Monday:
SMB2 features Resource compounding, allowing multiple requests to be sent in a single request. In addition, SMB2 can use large reads and writes to make better use of faster networks as well as large MTU support for blazing speeds on 10 Gigabit Ethernet. It aggressively caches file and folder properties and uses opportunistic locking to enable better caching of data. ItŐs even more reliable, thanks to the ability to transparently reconnect to servers in the event of a temporary disconnect.
OS X 10.9 will also continue to support the NFS 3 and NFS 4 file sharing standards for connecting to Linux and Unix servers, desktops, and devices. A new feature called AutoFS enables an administrator to specify automount paths for an entire organization using the standard Linux and Solaris automounter maps.