Will lion/mountain lion r/w/mount ext3 partitions?

No.

You'd have to run Linux in a virtual machine. I strongly recommend against trying to dual-boot.

You can absolutely mount ext2/3/4 drives within OS X using FUSE (MacFUSE). While MacFUSE is no longer in development, its latest version should allow you to mount and use a number of unsupported formats, including ext3.

1. Install MacFUSE: http://code.google.com/p/macfuse/

2. Install the ext2 FUSE module: http://sourceforge.net/projects/fuse-ext2/

3. Use Disk Utility to get the device name of the ext3 drive by enabling the debug menu and showing all partitions (see here: http://reviews.cnet.com/8301-13727_7-20081463-263/manage-all-partitions-with-dis k-utility-in-os-x/). Then select the ext3 partition and get info on it to get its device name (e.g., disk2s2).

4. Create a mount point by making a directory in your /Volumes folder or anywhere on your system.

5. Mount the ext3 drive with the following command in the Terminal (replace "disk2s2" with whatever your device name is, and likewise for the specified mount point):

fuse-ext2 /dev/disk2s2 /Volumes/mountpoint

To add write support, supply the "-o force" flag as follows:

fuse-ext2 -o force /dev/disk2s2 /Volumes/mountpoint

(No guarantee on good r/w performance, but it is an option)

While I have not used it, FUSE for OS X (or OSXFUSE) is a currently supported FUSE system that is the successor for MacFUSE, so you migth look into using this first; however, both should allow you to mount an ext3 filesystem.

http://osxfuse.github.com

I am having trouble geting the drive to be writable. I am getting the Socket is Not Connected message. What am I doing wrong?

Williams-MacBook-Pro:~ williamjones$ sudo fuse-ext2 -o force /dev/disk1s1 /Volumes/X360ISOS

Password:

fuse-ext2: version:'0.0.7', fuse_version:'27' [main (../../fuse-ext2/fuse-ext2.c:324)]

fuse-ext2: enter [do_probe (../../fuse-ext2/do_probe.c:30)]

fuse-ext2: leave [do_probe (../../fuse-ext2/do_probe.c:55)]

fuse-ext2: opts.device: /dev/disk1s1 [main (../../fuse-ext2/fuse-ext2.c:351)]

fuse-ext2: opts.mnt_point: /Volumes/X360ISOS [main (../../fuse-ext2/fuse-ext2.c:352)]

fuse-ext2: opts.volname: X360ISOS [main (../../fuse-ext2/fuse-ext2.c:353)]

fuse-ext2: opts.options: force [main (../../fuse-ext2/fuse-ext2.c:354)]

fuse-ext2: parsed_options: force,allow_other,local,noappledouble,fsname=/dev/disk1s1,fstypename=ext2,volna me=X360ISOS [main (../../fuse-ext2/fuse-ext2.c:355)]

fuse-ext2: mounting read-write [main (../../fuse-ext2/fuse-ext2.c:369)]

Williams-MacBook-Pro:~ williamjones$ mount_osxfusefs: failed to mount /Volumes/X360ISOS@/dev/osxfuse0: Socket is not connected

same here

HD (1T WD) works for reading but not for writing.

sudo fuse-ext2 /dev/disk2s1 /Users/someuser/mnt/ -o force,allow_other,local,noappledouble,rw+,fsname=/dev/disk2s1,fstypename=ext3,v olname=disk2s1

Password:

fuse-ext2: version:'0.0.7', fuse_version:'27' [main (../../fuse-ext2/fuse-ext2.c:324)]

fuse-ext2: enter [do_probe (../../fuse-ext2/do_probe.c:30)]

fuse-ext2: leave [do_probe (../../fuse-ext2/do_probe.c:55)]

fuse-ext2: opts.device: /dev/disk2s1 [main (../../fuse-ext2/fuse-ext2.c:351)]

fuse-ext2: opts.mnt_point: /Users/someuser/mnt/ [main (../../fuse-ext2/fuse-ext2.c:352)]

fuse-ext2: opts.volname: [main (../../fuse-ext2/fuse-ext2.c:353)]

fuse-ext2: opts.options: force,allow_other,local,noappledouble,rw+,fsname=/dev/disk2s1,fstypename=ext3,v olname=disk2s1 [main (../../fuse-ext2/fuse-ext2.c:354)]

fuse-ext2: parsed_options: force,allow_other,local,noappledouble,rw,fsname=/dev/disk2s1,fstypename=ext3,vo lname=disk2s1,allow_other,local,noappledouble,fsname=/dev/disk2s1,fstypename=ext 2,volname=disk2s1 [main (../../fuse-ext2/fuse-ext2.c:355)]

fuse-ext2: mounting read-write [main (../../fuse-ext2/fuse-ext2.c:369)]

[someplace:~] someuser% mount_osxfusefs: failed to mount /Users/someuser/mnt@/dev/osxfuse1: Socket is not connected