Troubleshooting for RHEL 5 server system

Time:2022-6-19

1、 /boot all the following files are missing: (grub, kernel, initrd ramdisk)

 

1. start with BootDisk, enter the liunx rescue mode, and select local install or NFS (HTTP)installmode

 

2. enter mold repair mode:

 

(1). cd /mnt/sysimage

 

Check what files (if empty)

 

(2) install kernel:

 

cd /mnt/source/Server

 

rpm -ivh kernel-2.6.18-53.el5.rpm –root=/mnt/sysimage –force

 

(3) Switch/

 

chroot /mnt/sysimage

 

(4) install grub

 

grub-install /dev/hda

 

(5) make initrd ramdisk

 

cd /boot

 

rm -rf initrd*

 

cd /lib/modules

 

mkinitrd /boot/initrd-2.6.18-8.el5.img 2.6.18-8

 

(6) vi /boot/grub/grub.conf

 

default=0

timeout=5

title Entprise Linux 5.0 2.6.18

root (hd0,0)

kernel /vlimuz.2.6.18.el5 ro root=LABEL=/1 rghb quiet

 

(Note: label can be viewed with e2label)

 

initrd /initrd-2.6.18-8.el5.img

 

(7).exit

 

(8) reboot

 

2、 /etc/inittab missing

 

Symptom: the set will not move after entering enter runlevel:

 

1. enter the rescue mode

 

2. chroot /mnt/sysimage

 

3. which package does rpm -qf /etc/inittab belong to

 

4.exit

 

5. cd /mnt/source/Server

 

rpm -ivh –replacepkgs –root /mnt/sysimage init……..rpm

 

6.reboot

 

3、 /etc/fstab missing

 

Symptom: starting system logger when detecting mount partition

 

1. enter rescue

 

2.mkdir /test

 

3.mount root partition

 

(1). Use fdisk -l to view the partition, and then use e2label to view the label name of each partition

 

(2) mount /dev/hda6 /test

 

(3) cd /test

 

(4) View the label name of each partition with e2label

 

Pay attention to the regularity: each label name is similar to the directory name to be mounted

 

(5). Refer to the contents of 4 VI /test/etc/fstab

 

LABEL=/1 / ext3 defaults 1 1

LABEL=/boot /boot ext3 defaults 1 1

LABEL=/usr1 /usr ext3 defaults 1 1

LABEL=/home /home ext3 defaults 0 0

/dev/hda7 swap swap defaults 0 0

 

Note: the principle is that the three partitions must be mount /, /boot, swap

 

(4) reboot