Pardon me while I get my geek on. While this doesn’t relate directly to storage, it does relate to everyone who develops or administers Mac OS X, one of my favorite operating systems (along with Tops-20). And it is another powerful feature that Microsoft’s Vista won’t have. As Apple puts it:

Track Down Problems
When you need a bit more help in debugging, Xcode 3.0 offers an extraordinary new program, Xray. Taking its interface cues from timeline editors such as GarageBand, now you can visualize application performance like nothing you’ve seen before. Add different instruments so you can instantly see the results of code analyzers. Truly track read/write actions, UI events, and CPU load at the same time, so you can more easily determine relationships between them. Many such Xray instruments leverage the open source DTrace, now built into Mac OS X Leopard.

Don’t let the Leopard reference mislead you. DTrace is now in the latest version of Apple’s Xcode development environment. Of course, it will still be there when Leopard rolls around.

A more technical definition of DTrace from Adam Leventhal’s Weblog is

DTrace, concisely, is a systemic observability framework that’s designed explicitly for use on mission-critical systems. It lets users and system administrators get concise answers to arbitrary questions.

Lest that “users” makes it sound like something your average web-surfing slacker – like me – might use, let me disabuse you right now.

Over at James Dicken’s blog he has a definition of DTrace that talks about what a “user” might do, including:

  • dynamically enable and manage thousands of probes
  • dynamically associate predicates and actions with probes
  • dynamically manage trace buffers and probe overhead
  • examine trace data from a live system or from a system crash dump

Read a little more about it here and here.

The DTrace announcement has other implications for storage, such whether we will see ZFS on Leopard. I’m working on parsing the Leopard Sneak Peek info in another window, so stay tuned.