Mount ext2 FS in MacOS X

**davidbrit2** · October 20th, 2002, 11:02 AM

:-) That is all.

**strobe** · October 21st, 2002, 05:41 PM

Originally posted by fddi1
Heh... I just had this idea, but not sure if it would work. If I installed Virtual PC and put RH Linux on it, would it recognize the mount?

No

**strobe** · October 21st, 2002, 06:00 PM

Originally posted by lethe
MacOSX uses the Mach 3.0 kernel. this is a microkernel. in fact, this is _the_ microkernel. windows NT-2000-XP also uses a microkernel. the GNU system (AKA GNU/HURD) also uses a microkernel, the mach 3 microkernel, the same as Mac OS X.

the darwin implementation of Mach 3.0 is known as xnu.

Wrong.

xnu is not Mach. xnu is based on a lot of technologies and borrows a lot from OSF Mach 3 including some technologies which aren't in Mach 3 like realtime threads.

Just to say it again for effect, xnu is not Mach.

by the way, strobe, having no native filesystems, and having dynamically loadable modules, while no definitive, does go a long way towards making a kernel a microkernel. every monolithic kernel has FS support hardwired in.

Not true. You can remove all filesystem support from Linux if you wish. The problem there is Linux would need to be able to load modules by another mechanism which isn't available on PCs. This mechanism is however available on Open Firmware so you could do this with Linux/PPC. However nobody would want to waste their time doing it.

However it could be done and Linux would still be called a macrokernel.

furthermore, whether or not it is a microkernel has _everything_ to do with how easy it is to add filesystem support. in fact, this was the whole principle behind the microkernel design. to make the kernel modular and extensible. it is much much easier and safer to add a filesystem module to a microkernel than to hardwire a new filesystem into a monolithic kernel. due to the obvious superiority of this architecture, even most monolithic kernels today have some support for dynamically loadable drivers, and therefore share some features with microkernels.

Umm... that is practically the definition of a microkernel.

Microkernel (from nightflight): An approach to operating system design emphasising small modules that implement the basic features of the system kernel and can be flexibly configured.

strobe: modules have quite a lot to do with microkernels. in fact they are the defining characteristic of a microkernel.

strobe, i am having my doubts as to whether you know what you re talking about, apropos kernel design. you should not be quite so aggressive in your posts, claiming someone does not know what [s]he is talkign about unless you are truly an expert, you know?

now as to whether the fact that OSX has a microkernel will help some end user, it is not likely. but remember, the easier it is for developers to add features, the more likely it is to happen, and that benefits our end user. and ease of extensibilty is the major force in the microkernel design.

The fundamental design of a microkernel is running 'servers' on separate threads which communicate to the kernel via messages. If you were correct in saying the defining characteristic of a microkernel is being modular then Linux would be a microkernel. Linux is not a microkernel.

You make it sound like Mac OS X modules are actually Mach modules (if there was such a thing). Apple even disuades people from using Mach threads and other Mach services directly in either application or driver development.

xnu is not a microkernel. xnu does not run servers, instead it is one giant binary. The BSD kernel does not run as a separate Mach server like it does in FreeBSD, NeXTSTEP, OPENSTEP, NetBSD, OpenBSD, MkLinux, or any other OS using the OSF Mach 3 kernel. Neither do the kernel modules run as Mach servers or processes.

**strobe** · October 21st, 2002, 06:03 PM

By the way GNU HURD doesn't use "the" Mach 3 microkernel, it uses its own version of the Mach 3 microkernel, not the OSF Mach 3 microkernel.

**strobe** · October 21st, 2002, 06:07 PM

Thinking further about VirtualPC, if you managed to create a disk image of your ext2 filesystem you might be able to use it with VirtualPC (even boot off it).

You could also put the hard drive in an external USB box since VirtualPC can use USB devices (you have to tell VirtualPC which USB devices to have absolute control over). I doubt you could boot off it, but you could probably read it if you have ext2 drivers for Windows or if Linux has support for USB drives.

Personally I would suggest taking my original suggestion and just booting off a Linux/PPC CD. You woudln't need to install Linux anywhere, just boot off the CD then move your files to a volume Mac OS X can read.

**Rhino_G3** · October 26th, 2002, 01:42 PM

This may sound like a stupid question but does Linux PPC support HFS+?

**buc99** · October 27th, 2002, 09:49 AM

So after much bickering about microkernels ...

I guess the point is that OSX does NOT recognize the ext2 filesystem. There is a project going on on sourceforge, but like most of the projects there, there is no documentation about what is going on. I guess I'll have to try to contact someone connected to the project to see what is up and what needs to be done.

Well. The only solution I can see is to use Virtual PC as a go between for my situation. Or reformat my SD card to the less than optimal Fat file system. Oh well. Maybe OSX will get something going someday.

Thanks.
SA