RHCE footprint: Fixed bad boot partitions and grub

Environment: The/boot partition is completely damaged, and the MBR is also damaged. (Rm-rf/boot; fdisk/mbr) 1. Fixed Grub: a. Start the disc and enter rescue mode. Keywords: linuxrescue. B. Enter the real system environment. Keywords: chroot/mnt/sysimagec. Install grub in the/boot partition. In this tutorial, the grub folder is installed under the boot partition, including the stag environment:
The/boot partition is completely damaged, and the MBR is also damaged. (Rm-rf/boot; fdisk/mbr)

1. Repair Grub:
A. Start the disc and enter rescue mode. Keywords: linux rescue.

B. Enter the real system environment. Keywords: chroot/mnt/sysimage

C. Install grub to the/boot partition. In this tutorial, the grub folder is installed under the boot partition, including stage1, stage2, and other files. Kewords: grub-install (hdx). If there is only one hard disk, It is 0. If you have multiple hard disks and the hard disk where the/boot partition is located is unknown, check fdisk-l first (the partition with the Id category of 83 and marked as Boot, and the hard disk)

D. Enter grub shell, keywords: grub.

E. Specify the root partition (that is, the boot partition) of grub ). Keywords: root (hdx, y). If there is only one hard disk, It is 0. If there are multiple hard disks and the hard disk where the/boot partition is located is unknown, refer to the fdisk-l check method above to obtain the x and y values. You can also press the tab key to view the hard disks and partitions detected by grub.

F. Install grub to MBR (actually copy stage1 to MBR ). Keywords: setup (hdx ).

2. Install kernel and initrd:
A. Attach the first disc. Keywords: # mdkir/mnt/cdrom; # mount-o loop/dev/hdc/mnt/cdrom

B. Find and install the rpm package of the kernel, and then install the vmlinuz, initrd, and other files required for the startup. Keywords: # cd/mnt/cdrom/Server; # rpm-ivh -- force kernel-2.6xxxxx.rpm

3. Create/boot/grub. conf. At least the following lines are required:

Timeout 5 # I think it is necessary not to enable it, but it cannot be automatically restarted.
Title RedHat Linux EL5 # title you can write any text, but this line is required.
Root (hdx, y) # note the space behind the root. For more information about x and y, see the preceding section.
Kernel/vmlinuz-2.6.18-8.el5 ro # standard installation, followed by a possible root = LABEL =/class options, but it is not actually necessary, and, on a system with raid + lvm configured, this option may cause the system to fail to start. The reason is that the root partition and its partition cannot be found. "/" Indicates the boot partition.

Initrd/initrd-2.6.18-8.el5.img # specifies the location of the initrd image file. "/" Indicates the boot partition.

4. OK. press exit twice to restart.