Delete system files and repair them

Delete system files and repair 1 Delete all files under the boot directory [plain] # delete/boot, then restart [root @ serv01 boot] # rm-rf * [root @ serv01 boot] # ls [root @ serv01 boot] # reboot # an Error occurs. Error 15 # Shut down the VM., then use the disc Drive, pay attention to the memory adjusted to 800 M; restart the computer, at the moment of startup, Press ESC key, enter the Boot Menu, choose CD-ROM Drive # enter the Boot interface, select Rescueinstalled system, Choose a language, select English, Keyboad Type select us, Rescue method select Local CD/DVD, Setup networking select no, Rescue select Contiune, Rescue Select OK, select OK again on the next page, shell st Art shell, start shell. # It is found that bash is entered, and cd/boot is unavailable at this time # Enter chroot/mnt/sysimage to enter/, and then enter/boot. It is found that bash is changed to sh # configure yum source, ls/iso mount/dev/cdrom/iso # reinstall the kernel yum reinstall kernerl-y # You can also use rpm to install rpm-ivhkenerl-xxx -- force -- replacefiles # install grub-install /dev/sda # exit sh exit # Enter bash, then restart reboot # Enter grub, execute the following in sequence (press the Tab key) root (hd0, 0) kernel/vmlinuz-2.6.32-131.0.15.el6.x86_64 initrd/initramfs-2.6.32-131.0.15.el6.x86_64.img boot # re-import Run root (hd0, 0) kernel/vmlinuz-2.6.32-131.0.15.el6.x86_64 initrd/initramfs-2.6.32-131.0.15.el6.x86_64.img boot # repair successful, you can edit grub. conf file. You will not reboot next time, grub. the conf file is as follows: [root @ serv01 opt] # cd/boot/grub/[root @ serv01 grub] # vim grub. conf [root @ serv01 grub] # cat grub. conf default = 0 timeout = 5 title RedHat Server 6.1 root (hd0, 0) kernel/vmlinuz-2.6.32-131.0.15.el6.x86_64 ro root =/dev/sda2 initrd/initra Mfs-2.6.32-131.0.15.el6.x86_64.img [root @ larrywen/] # ssh 192.168.1.11 root@192.168.1.11's password: Last login: Wed Jul 31 18:05:19 2013 from192.168.1.1 # It is recommended to put the/boot partition in the first location two rc. sysinit file loss [plain] # rc. the sysinit file is lost and enters the repair mode. You only need to reinstall (copy) the file to [root @ serv01 grub] # ls/etc/rc. d/rc. sysinit/etc/rc. d/rc. sysinit # installation error [root @ serv01 grub] # yum install/etc/rc. d/rc. sysinit # reinstall [root @ serv01 grub] # yum reinsta Ll/etc/rc. d/rc. sysinit [root @ serv01 ~] # Rpm-qf/etc/rc. d/rc. sysinit initscripts-9.03.23-1.el6.x86_6 # Other System File loss, similar to Operation 3 grub. the conf file is deleted [plain] # You can see/etc/grub. conf/boot/grub. conf is the same file [root @ serv01 ~] # Ls/etc/grub. conf/boot/grub. conf-l-rw -------. 1 root 817 Jul 30/boot/grub. conf lrwxrwxrwx. 1 root 22 Jul 23 00:57/etc/grub. conf-> .. /boot/grub. conf # Delete grub. cannot be resolved after the conf file # Step 1: view disk partitions [root @ serv01 ~] # Df-h Filesystem Size Used Avail Use % Mounted on/dev/sda2 9.7G 1.1G 8.1G 12%/tmpfs 188 M 0 188 M 0%/dev/shm/dev/sda1 194 M 25 M 160 M 14%/boot/dev/sda5 4.0G 137 M 3.7G 4%/opt/dev/sr0 3.4G 3.4G 0 100%/iso # Enter the directory to delete grub. conf file [root @ serv01 ~] # Cd/boot/grub/[root @ serv01 grub] # rm-rf grub. conf [root @ serv01 grub] # reboot # input these commands in sequence root (hd0, 0) # In this step, press and hold the tab key to automatically complete the kernel/# And add root =/dev/sda2 to the end. Note that your machine is not necessarily/dev/sda2, you want to view which partition the root partition belongs to through df-h kernel/vmlinuz-2.6.32-131.0.15.el6.x86_64ro root =/dev/sda2 # Press and hold the tab key and the initrd/initramfs-2.6.32-131.0.15.el6.x86_64.img is automatically completed # Note, if you have multiple kernels, You need to select # Enter boot and restart # enter the boot directory after restart. The file [root @ serv01 ~] # Cd/boot/grub/[root @ serv01 grub] # ls grub. conf ls: cannot access grub. conf: No such fileor directory # The next time we start the file, we will find that we need to re-boot the file. At this time, we will re-create the file and enter the following content. # Here is a tip, when using vim to edit files, you can read and copy commands in command mode (! Indicates executing the command) r! Ls/boot/initramfs-2.6.32-131.0.15.el6.x86_64.img [root @ serv01 grub] # vim grub. conf [root @ serv01 grub] # cat grub. conf default = 0 timeout = 5 title RedHat Server 6.1 root (hd0, 0) kernel/vmlinuz-2.6.32-131.0.15.el6.x86_64 ro root =/dev/sda2 initrd/initramfs-2.6.32-131.0.15.el6.x86_64.img [root @ larrywen grub] # ls device. map splash.xpm.gz [root @ serv01 grub] # find. -name "* stage *". /minix_stage1_5. /stage1./ Xfs_stage1_5. /ufs2_stage1_5. /ffs_stage1_5. /e2fs_stage1_5. /stage2. /jfs_stage1_5. /iso9660_stage00005. /vstafs_stage1_5. /fat_stage1_5. /reiserfs_stage1_5 # deleting all files with stages does not affect the operation. The restart is still normal [root @ serv01 grub] # find. -name "* stage *" | xargs rm-rf {}\; [root @ serv01 grub] # ll total 8-rw-r --. 1 root 63 Jul 23 00:57 device. map-rw-r --. 1 root 170 Jul 31 grub. conf lrwxrwxrwx. 1 root roo T 11 Jul 23 00:57 menu. lst->. /grub. conf-rw-r --. 1 root 1341 May 7 2010splash.xpm.gz 4 go to the boot directory, delete all the files, and restore [plain] [root @ serv01 ~] while continuously enabling connections # Cd/boot [root @ serv01 boot] # ls config-2.6.32-131.0.15.el6.x86_64 initramfs-2.6.32-131.0.15.el6.x86_64.img System. map-2.6.32-131.0.15.el6.x86_64 efi lost + found vmlinuz-2.6.32-131.0.15.el6.x86_64 grub symvers-2.6.32-131.0.15.el6.x86_64.gz [root @ serv01 boot] # rm-rf * [root @ serv01 boot] # ll total 0 # Step 1, install grub [root @ serv01 boot] # grub-install/dev/sda Probing devices to guess BIOS drives. thismay t Ake a long time. installation finished. no error reported. this is the contents of the device map/boot/grub/device. map. check if this is correct or not. if any ofthe lines is incorrect, fix it and re-run the script 'grub-install '. (fd0)/dev/fd0 (hd0)/dev/sda # Step 2: Install kernel [root @ serv01 boot] # yum reinstall kernel-y Loaded plugins: product-id, subcategory-manager Updating Red Hat repositories. S Etting up Reinstall Process rhel-iso | 4.0 kB... resolving Dependencies --> Running transaction check ---> Package kernel. x86_640: 2.6.32-131.0.15.el6 will be installed --> Finished Dependency Resolution Dependencies Resolved ================== ========================================================== ========================================================== ====================== Package Arch Version Repository S Ize ===================================================== ========================================================== ========================================================== ================== Reinstalling: kernel x86_64 2.6.32-131.0.15.el6 rhel-iso 23 M Transaction Summary ==================== ========================================================== ========================================================== ======================================= Reinstall 1 Package (s) total download size: 23 M Installed size: 108 M Downloading Packages: Running rpm_check_debug Running Transaction Test Succeeded Running Transaction Installing: kernel-2.6.32-131.0.15.el6.x86_64 1/1 duration: 263 (MS) Installed products updated. installed: kernel. x86_64 0: 2. 6.32-131.0.15.el6 Complete! [Root @ serv01 boot] # ls config-2.6.32-131.0.15.el6.x86_64 initramfs-2.6.32-131.0.15.el6.x86_64.img System. map-2.6.32-131.0.15.el6.x86_64 grub symvers-2.6.32-131.0.15.el6.x86_64.gz vmlinuz-2.6.32-131.0.15.el6.x86_64 # Go To The grub directory and create a new grub. conf file [root @ serv01 boot] # cd grub/[root @ serv01 grub] # ll total 268-rw-r --. 1 root 30 Jul 31 device. map-rw-r --. 1 root 13396 Jul 31 00:44 e2fs _ Stage1_5-rw-r --. 1 root 12620 Jul 31 fat_stage00005-rw-r --. 1 root 11764 Jul 31 ffs_stage00005-rw-r --. 1 root 11772 Jul 31 iso9660_stage1_5-rw-r --. 1 root 13300 Jul 31 jfs_stage1_5-rw-r --. 1 root 11956 Jul 31 minix_stage1_5-rw-r --. 1 root 14444 Jul 31 reiserfs_stage1_5-rw-r --. 1 root 512 Jul 31 00:44 st Age1-rw-r --. 1 root 126040 Jul 31 00: 44stage2-rw-r --. 1 root 12040 Jul 31 ufs2_stage1_5-rw-r --. 1 root 11396 Jul 31 vstafs_stage1_5-rw-r --. 1 root 13980 Jul 31 xfs_stage00005 [root @ serv01 grub] # vim grub. conf # file content: [root @ serv01 grub] # cat grub. conf default = 0 timeout = 5 title Redhat Server 6.1 root (hd0, 0) kernel/vmlinuz-2.6.32-131.0.15.el6.x86_64 Ro root =/dev/sda2 quiet initrd/initramfs-2.6.32-131.0.15.el6.x86_64.img [root @ serv01 grub] # reboot Broadcast message from root@serv01.host.com (/dev/pts/0)... the system is going down for reboot NOW! [Root @ serv01 grub] # Connection to192.168.1.11 closed by remote host. Connection to 192.168.1.11 closed. # restart and reconnect. The Connection is successful. OK! [Root @ larrywen Desktop] # ssh 192.168.1.11 root@192.168.1.11's password: Last login: Wed Jul 31 00:43:50 2013 from192.168.1.1 [root @ serv01 ~] #