Windows下安装linux双系统

Question

（不知道图片为什这样，麻烦对付看一下）

安装Windows和linux双系统
空闲为50G，在分出了/boot和swap分区后，变成了不可用，为什么？

另外，哪个分区是必须有的？

Answer 1

I assume you are using MBR, it can only have 4 primary partitions or 3 primary partitions and 1 extended partition.

Seems like Ubuntu can not recognize the extended partition.

You can create the partitions under windows such as /dev/sda7. And mount it on /.

Or install the Ubuntu on the whole partition like /dev/sda3(extend the size under windows before install).
This need mount the whole partition on /.