Ext4 is stable now, and was an easy upgrade from ext3, both in terms of development and in terms of converting your existing filesystems -- one command, and then just remount as ext4, no time-consuming and dangerous conversion needed.

BtrFS looks to be better than ext4 in every way except the above -- and I haven't been following it for awhile, so as far as I know, btrfs might be rock-solid stable by now.

Put another way, ext4 is a replacement for ext3, whereas btrfs is a replacement for zfs.

With GRUB ~= 2.0, you aren't supposed to mess with grub.conf. You're supposed to mess with a shitpile of external .conf files and command line tools.

Ext4 is a more error-resistant (safer) and potentially faster Ext3. If you don't know what BtrFS is good for, you don't need to use BtrFS (although it could become a mainstream filesystem some day).

I think you mean that btrfs is a replacement for ext4. Maybe I'm naive and a bit reactionary but I'm just not seeing FreeBSD and Solaris switching to btrfs just because the Linux crowd says it's the greatest thing since sliced bread...

If you get random file corruption on Windows, you either have serious hardware failure or use Windows 98.

Fixed that for you...
Now with grub2 you have three config files (at least in Ubuntu); a read-only /boot/grub/grub.cfg, an /etc/default/grub with some stuff in it and a couple of files in /etc/grub.d/
Once you change anything in one of them you have to run 'update-grub' and it'll generate the grub.cfg from the other files.

- Peder