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Linux on Intel Macs

At Mac Musings: OS X Is Holding Back the Mac, Dan Knight suggests that Apple should abandon its BSD based Mach kernel and switch to Linux.

It is an interesting thought, but not very likely for the obvious reasons: tremendous investment in the current OS, the cost of development, and the resulting "me-too" OS. Maybe Apple could make a better Linux than anyone else has so far, but so what? How would that help Apple?

Dan says it would help performance:

The problem with Mach is that microkernels are inefficient
because of all the communication taking place between different
parts of the operating system. A monolithic kernel is more
efficient because processes don't have to move in and out of
the kernel.

Umm, OK, let's just take that as absolute truth (in spite of the fact that there are people who would argue that and insist that even if it is true the benefits outweigh any disadvantage). Whenever anyone talks about speed hampering anything, we have to remember that hardware keeps careening along getting ever faster and faster. Charges of inefficiency, bloat or anything else in that line are about as important as worrying about the color of the case: it barely matters to anyone except a few gamers and some folks doing massive number crunching. Nobody else is affected, or if they are, they won't be next week or next year.

What do you spend your day doing? I'm browsing web pages and typing - one of which is limited by my cable modem and the other by my finger skills. Sure, now and then I'd like something to happen faster, but it's pretty rare. Speed is not something I think about much nowadays.

So Apple switching to Linux would only be bad news for them. Not that I won't be running Linux in a virtual machine on my Intel Mac the minute that becomes possible. This isn't about the value of running Linux on Macs; that's a given in my world. But I see no incentive for Apple to move its kernel to Linux.

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© Anthony Lawrence

Thu Feb 16 14:07:46 2006: 1647   drag

The funny thing about this 'Mach being a Microkernel' is that in fact Apple doesn't actually _use_ _mach_.

They use code FROM Mach, but not the Mach kernel itself. It's a sort of conglomeration between BSD and Mach kernels. The Mach portion loads up, does it's thing, then loads up the BSD half of the kernel in some sort of messaging arrangement. This isn't the same as 'Microkernel' with various usermode client portions like is used with the Hurd or older Mach stuff.. but it all exists in the same kernel memory space so it's a monolithic kernel.

I think it's a sort of a marketting thing.. Microkernels sound in practice to be very attractive things to techies, except for the size, complexity, and performance penatly. Microsoft said NT used a microkernel, but it realy doesn't, so Apple is kinda pulling the same trick.

It's actually called the XNU kernel

Linux itself is probably superior to XNU kernel and Linux servers are going to probably be better servers then OS X does.

You have a lot more features, lot higher flexibility. Xen, various clustering doo-dads, GFS, etc etc. Linux will work with most people's existing hardware and has a lot more hardware options. A lot more I/O options. etc etc.

OS X's file system is a lot more fragile then Ext3, HFS+ is Apple's OS 9 file system with a Unix-like layer over it based on the BSD VFS stuff. Same thing with it's journalling features... Ext3's journalling features have no performance penalty unless you want to enable data journalling (Ext3 supports various levels of journalling). You have LVM. You have software raid and lots of hardware raid options. You have probably better SAMBA support.

And it's faster. Linux devs have speed at a very high priority. XNU looses to Linux in this catagory not so much because XNU has microkernel aspects, but it looses just because Linux is very fast.

All sorts of stuff makes Linux superior at being servers.

But OS X servers can be perfectly capable and if they can fuffill the job requirements then I don't see any real reason to avoid them.

OS X for the Desktop is still very much better for the average person then Linux for a lot of things, I wouldn't hold it's performance or file system aspects against it for that because, like you, I don't think matter that much compared to other things. (just as long as you do good backups.. which is a requirement for any system you want to use)

I think that if Apple wanted to switch to a GNU/Linux base rather then a BSD/XNU based OS I don't think it would be _that_ _hard_. The most difficult thing would be to provide a compatability layer for OS X applications and the file system (they don't go: /directory/filename, they go volumename:directoryname:filename, for instance. Then you have the resource forks and such) or porting HFS+ to be stable for Linux. I don't see much of a improvement at this time though.

Thu Feb 16 19:21:47 2006: 1649   bruceg2004

Let's just hope this rumor is not true, and if it is - that they will Opensource OS X - this would break my heart if it ever came true. I love the OS X interface, and the BSD Unix running beneath it.


Also, there seems a trojan horse has infected some OS X users:


I guess we have to take the bad news, with the good news!

Thu Feb 16 19:24:36 2006: 1650   bruceg2004

It seems that link is broken, or slashdoted, but basically it talks about the possibility of Apple running WINDOWS!! Man that is a horrible thought. Why? Why? Why? It would tick a lot of people off...

Editor: Link is working now so I've deleted the comments that pasted Dvorak's article here.

Thu Feb 16 22:27:25 2006: 1653   TonyLawrence

When the link works again I'll take out the illegal copying :-)

The professor is all wet. People HAVE switched, and more will yet.

If Apple wanted to do that at all, the obvious path to it is through virtualization, which would keep everybody happy: put up a hypervisor and the user has both OSes (if that's what they want).

Remember that Darwin is also an open source project, so even if this were in the wind, there would be a large community dedicating to keeping you on the OS you like.

Dvorak is a bright guy, but often way out in left field.

Fri Feb 17 00:57:11 2006: 1654   bruceg2004

Yes, I switched, and have 2 friends, and 3 on the bubble that switched, and I have not had to help either of the two who switched with any issues.

Even with the so called OS X trojan horse, I told both of my friends who switched, that if an attachment in an email or a file posted someplace that you are not 100 sure of asks you for your password CANCEL it!! That is why this malware does not spread on the Mac. Nothing can make it past the user level, if the user has a little bit of training. Why has it taken Microsoft so long to figure that out?

Yes, I often disagree with Dvorak. About the only thing I agreed with him on, is when he backed OS/2, because it was superior to Windows at the time. Heck, it may still be. I always take his predictions with a salt shaker, and this one I originally heard on the TwiT podcast, and I almost screamed "No Way" when I heard it. I knew when his column appeared that it would stir up some people.

Thanks for deleting my plagiarism. Everyone linked to the article today, and it overwhelmed those MS .asp files. I just had to let you and the others on pcunix.com read it. So hard to swallow.

The virtualization makes much more sense. "Seamless Windows" has been proposed, and would make everyone happy. Even MS would get a cut, since they sell a license. They are probably 3/4 of the way there with virtual PC.

I have just come to love Mac applications, and how the GUI is laid out. There seems to be a standard for most well designed Mac applications, and they are just so easy to use, as well as powerful. Apple really has a winner in OS X, and it is light years ahead of Windows. Most of the new features MS is touting in Vista, are already available in OS X! Why Dvorak would think that Steve would step backwards is so hard to believe. As long as publishers continue to design "real" Mac apps, and not half *redacted* ports from a Windows version, I am happy.

- Bruce

Fri Feb 17 12:53:08 2006: 1655   bruceg2004

Oh yea - my wife has switched too! We are now a 100 Mac household. My wish has come true!

- Bruce

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