这是一些背景。我有一个 1TB 硬盘，里面装有 Windows。分区是这样的：
我购买了另一个 2TB 硬盘，并希望将 1TB 专用于 Windows，另一个专用于 Linux。这是第二个硬盘的屏幕截图。
正如你所看到的，sda2在安装 CentOS 7 时有 Windows 引导加载程序。我故意尝试在第一个硬盘驱动器中安装 CentOS 引导加载程序（即 grub？），以便 CentOS 可以检测到它。但似乎 CentOS 即使在那之后也无法检测到 Windows。
fdisk -l如果屏幕截图还不够，这是我的输出：
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes, 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: gpt
# Start End Size Type Name
1 34 262177 128M Microsoft reser Microsoft reserved partition
Partition 1 does not start on physical sector boundary.
2 264192 1953646591 931.5G Microsoft basic Basic data partition
3 1953646592 1955743743 1G Microsoft basic
4 1955743744 3907028991 930.5G Linux LVM
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
Disk /dev/sda: 1000.2 GB, 1000204886016 bytes, 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: gpt
# Start End Size Type Name
1 2048 616447 300M Windows recover Basic data partition
2 616448 819199 99M EFI System EFI system partition
3 819200 1081343 128M Microsoft reser Microsoft reserved partition
4 1081344 1048575999 499.5G Microsoft basic Basic data partition
5 1048576000 1887436799 400G Microsoft basic Basic data partition
6 1887436800 1953521663 31.5G Microsoft basic Basic data partition
7 1953521664 1953523711 1M BIOS boot parti
Disk /dev/mapper/cl-01: 981.9 GB, 981873983488 bytes, 1917722624 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/mapper/cl-00: 17.2 GB, 17179869184 bytes, 33554432 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/mapper/luks-13bc4611-477c-4df5-bfb7-b2bbd696e18b: 981.9 GB, 981871886336 bytes, 1917718528 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
我研究了一下并发现我可以执行update-grub命令。但这在这里是不可能的。 CentOS 7 使用的 grub 与 Ubuntu 的 grub 不同（如果我错了，请纠正我）。
我还找到了一个grub2-mkconfig 方法，但此命令找不到 Windows 引导加载程序：
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-3.10.0-514.26.2.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-514.26.2.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-514.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-514.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-fd2ff737d87642cc87d59785cf5f2390
Found initrd image: /boot/initramfs-0-rescue-fd2ff737d87642cc87d59785cf5f2390.img
done
这是一台支持 UEFI 的计算机。
我有了一个发现，发现了这个：
这个有什么用吗？