Grub2 is a disaster for me and maybe (probably) ext4 belongs to it too. I'm doing all with Linux. No Windows yet again after I used it formerly until Windows ME.
I'm happy to say that I managed to keep my Linux multiboot-system okay in spite of my (intens) testing ext4 and Grub2. I did it on another HD with dummy OS's. Else I would have had a completely broken system. But I knew before that things could become tricky. So I kept the safe side.
Now I stick to a good multiboot system with for example PCLinuxOS, XKUbuntu, still with Mint 6 (+bootloader) and Mint 8 Helena as latest Mint and some more partition to move, and the whole thing on ext3. Not on ext4.
And what for ext4? I don't see the benefits. It is even not much faster.
But this 'sticking' of me can't go on for always, I know Ubuntu and Mint.
Before one knows one is working with a tool from the 'stone-age'. Very, very short release-cycle.
I have problems for instance:
when I use some distro's without
a bootloader and one with
a bootloader where in former days a
Mint- of Ubuntu-distro made a fine list in Grub's menu.lst of entrees, when the bootloader was 'on'.
You could repeat that chainloading principle over and over again. Very nice. I don't see the fun of /etc/Grub.d.
And so you can experiment and test as much as you like with distro's along each other on several partitions.
But with ext4 and Grub2 I even can't do a 'redo-MBR' to get Grub-things right.
I use remastersys to keep things safe enough. Supertool. But not anymore it looks like.
Remastersys too has suddenly problems because of Grub2 or ext4 when I'm installing an OS to another
disc for example, where things formerly went always smooth.
I hope this is temporalily. I also hope, this is not a bug or something like that, so I'm worrying for nothing.
The possibillity to play around with OS's and also doing my work with them was a very important reason for me to do things Linux. Very comfortable it was..
I hope the Grub2-ext4 story is not a risk for Linux as a whole?!