I went through a lot of articles on how to create bootable os x install partition but eventually I ended up with a need of making resize of my system partition - unfortunately DiskUtility shows this option greyed out. Any ideas why? I don't want to loose my existing system installation.
Properties say that it is a physical volume and it's not using CoreStorage. This is the output of diskutil list command:
And it seems like I managed to resize this disk0s2 partition with:
diskutil resizeVolume disk0s2 480GB
command. Still don't get why this option is absent in DiskUtility. It used to be there. And unfortunately this is not what I was looking for. After I resized this volume DiskUtility didn't allow me to create a new partition. Therefore I think the problem is in that I didn't partition drive properly from the very beginning. diskutil splitPartition doesn't work at all - it says that it cannot unmount disk. Any ideas other than to wipe HDD contents out and install from scratch? I don't want to install Snow Leopard first and update it to El Capitan.