centos boot修复,centos怎么安装软件包
centosboot分区删除怎么恢复
第一步
重启之后,按ESC键选择CDROM引导,输入linuxrescue再次进入到修复模式。
其实这是可以setup修改IP地址,然后servicenetworkrestartservicesshdstart用ssh远程登入操作可以复制最后的操作
此时再次进入到修复模式时,rescue程序将会找到fstab文件,也就是会找到linux分区!并且把损坏的原linux系
统挂载到/mnt/sysimage下。并且rescue程序会提示你,可以使用#chroot(changeroot修改根目录)修改根目录
。
第二步
选择OK之后,系统已经全部挂载到了/mnt/sysimage,如果想进去,敲入#chroot/mnt/sysimage,修改根目
录为/mnt/sysimage,使用ls命令可以查看原系统里的文件和目录。使用exit可以退回rescue程序下,再次使用ls
命令可以比较一下区别。
第三步
#mount/dev/hdc/mnt/source---挂载光驱cdrom到/mnt/source目录
#rpm-ivh/mnt/source/Server/kernel-2.6.18-164.e15.i686.rpm--root=/mnt/sysimage/--force
(需要修复的三个内核文件在系统盘server目录下kernel-2.6.18.rpm软件包里,所以要挂载光盘之后并安装
kernel软件包)
第四步
此时,内核已修复完成!再继续修复grub程序。。。
#chroot/mnt/sysimage进入到已损坏的linux系统中
#grub-install/dev/sda安装grub程序到/dev/sda
#ls/boot/grub查看grub目录下是否存在grub.conf文件。如果没有就手动编辑一个。
#vim/boot/grub/grub.conf
第五步
vim/boot/grub/grub.com
手动编辑grub.conf配置文件内容如下:
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
titleCentOS(2.6.32-431.el6.x86_64)
root(hd0,0)
kernel/vmlinuz-2.6.32-431.el6.x86_64roroot=UUID=7790ca5d-9125-45b7-ae7f-6630ffec73bcrd_NO_LUKSKEYBOARDTYPE=pcKEYTABLE=usrd_NO_MDcrashkernel=autoLANG=zh_CN.UTF-8rd_NO_LVMrd_NO_DMrhgbquiet
initrd/initramfs-2.6.32-431.el6.x86_64.img
如何修复centos引导
试了多种方法均不能重建MBR,安装GRUB引导,差点就想重装CentOS系统了,最后想在用CentOS LiveCD修复,但是用LiveCD进入图形界面后也无法修复。摸索多次后,最后用LiveCD的文本模式才将硬盘的MBR重建OK,现记录过程以便以后查阅。
1、用LiveCD进入文本模式,用mount查看硬盘挂载情况;
2、建立boot文件夹 mkdir/mnt/sda1/boot
3、将引导分区挂载到/mnt/sda1/boot,用mount/dev/sda1/mnt/sda1/boot-o rw重新挂载为可读写,因当默认挂载是只读;
4、用/mnt/sda1为主文件夹安装GRUB引导 grub-install--root-directory=/mnt/sda1/dev/sda;
5、重启OK。
如果不把引导分区挂载到boot中重建MBR后将会在sda1下建立一个boot文件夹,但是在boot\grub\文件夹中会丢失grup.conf而导致启动时出现grub>的提示不能正常启动。可能原因估计是linux系统会自动将引导分区挂载到/boot中,所以当你指--root-directory=/mnt/sda1时会自动查找sda1下的boot文件夹,如果没有boot文件夹就会自动创建。
CentOS7网络设置修复
服务器有两个网卡enp7s0和enp8s0
服务器需要通过enp8s0和互联网联通,互联网为笔记本转接
通过centos7界面修改ip,失败;
通过centos7的网络配置文件/etc/sysconfig/network-scripts/ifcfg-enp8s0修改ip设置
设置如下:
1.启动 service network start报错,通过journalctl-xe查看如下
-- Defined-By: systemd
-- Support:
--
-- Unit fprintd.service has begun starting up.
12月 29 19:31:12 crrchost dbus-daemon[851]: dbus[851]: [system] Successfully activated service'net.reactivated.Fprint'
12月 29 19:31:12 crrchost dbus[851]: [system] Successfully activated service'net.reactivated.Fprint'
12月 29 19:31:12 crrchost systemd[1]: Started Fingerprint Authentication Daemon.
-- Subject: Unit fprintd.service has finished start-up
-- Defined-By: systemd
-- Support:
--
-- Unit fprintd.service has finished starting up.
--
-- The start-up result is done.
12月 29 19:31:12 crrchost fprintd[6685]: Launching FprintObject
12月 29 19:31:12 crrchost fprintd[6685]:** Message: D-Bus service launched with name: net.reactivated.Fprint
12月 29 19:31:12 crrchost fprintd[6685]:** Message: entering main loop
12月 29 19:31:18 crrchost polkitd[835]: Operator of unix-session:1 successfully authenticated as unix-user:windfarm to gain TEMPORARY authorization for action org.freedesktop.systemd1.manage-units for system-bus
12月 29 19:31:18 crrchost systemd[1]: Starting LSB: Bring up/down networking...
-- Subject: Unit network.service has begun start-up
-- Defined-By: systemd
-- Support:
--
-- Unit network.service has begun starting up.
12月 29 19:31:18 crrchost network[6693]:正在打开环回接口: [ 确定 ]
12月 29 19:31:18 crrchost network[6693]:正在打开接口 enp7s0:
12月 29 19:31:24 crrchost network[6693]:正在确定 enp7s0的 IP信息...失败:不存在链接。检查电缆?
12月 29 19:31:24 crrchost network[6693]: [失败]
12月 29 19:31:24 crrchost network[6693]:正在打开接口 enp8s0: RTNETLINK answers: File exists
12月 29 19:31:25 crrchost network[6693]: [ 确定 ]
12月 29 19:31:25 crrchost network[6693]: RTNETLINK answers: File exists
12月 29 19:31:25 crrchost network[6693]: RTNETLINK answers: File exists
12月 29 19:31:25 crrchost network[6693]: RTNETLINK answers: File exists
12月 29 19:31:25 crrchost network[6693]: RTNETLINK answers: File exists
12月 29 19:31:25 crrchost network[6693]: RTNETLINK answers: File exists
12月 29 19:31:25 crrchost network[6693]: RTNETLINK answers: File exists
12月 29 19:31:25 crrchost network[6693]: RTNETLINK answers: File exists
12月 29 19:31:25 crrchost network[6693]: RTNETLINK answers: File exists
12月 29 19:31:25 crrchost network[6693]: RTNETLINK answers: File exists
12月 29 19:31:25 crrchost systemd[1]: network.service: control process exited, code=exited status=1
12月 29 19:31:25 crrchost systemd[1]: Failed to start LSB: Bring up/down networking.
-- Subject: Unit network.service has failed
-- Defined-By: systemd
-- Support:
--
-- Unit network.service has failed.
--
-- The result is failed.
12月 29 19:31:25 crrchost systemd[1]: Unit network.service entered failed state.
12月 29 19:31:25 crrchost systemd[1]: network.service failed.
12月 29 19:31:25 crrchost polkitd[835]: Unregistered Authentication Agent for unix-process:6669:319312(system bus name:1.263, object path/org/freedesktop/PolicyKit1/AuthenticationAgent, locale zh_CN.UTF-8)(d
3.systemctl status network.service查看如下:
● network.service- LSB: Bring up/down networking
Loaded: loaded(/etc/rc.d/init.d/network; bad; vendor preset: disabled)
Active: failed(Result: exit-code) since六 2018-12-29 18:38:17 CST; 1min 24s ago
Docs: man:systemd-sysv-generator(8)
Process: 909 ExecStart=/etc/rc.d/init.d/network start(code=exited, status=1/FAILURE)
12月 29 18:38:06 crrchost systemd[1]: Starting LSB: Bring up/down networking...
12月 29 18:38:06 crrchost network[909]:正在打开环回接口: [ 确定 ]
12月 29 18:38:06 crrchost network[909]:正在打开接口 enp7s0:
12月 29 18:38:12 crrchost network[909]:正在确定 enp7s0的 IP信息...失败:…?
12月 29 18:38:12 crrchost network[909]: [失败]
12月 29 18:38:17 crrchost network[909]:正在打开接口 enp8s0: [ 确定 ]
12月 29 18:38:17 crrchost systemd[1]: network.service: control process exi...=1
12月 29 18:38:17 crrchost systemd[1]: Failed to start LSB: Bring up/down n...g.
12月 29 18:38:17 crrchost systemd[1]: Unit network.service entered failed...e.
12月 29 18:38:17 crrchost systemd[1]: network.service failed.
Hint: Some lines were ellipsized, use-l to show in full.
1.参考网络方法停用NetworkManager,依旧报错
systemctl stop NetworkManager
systemctl disable NetworkManager
2.比对两个网卡的MAC地址和配置文件的MAC地址
a.查看mac地址配置,ipconfig
b.查看配置文件中的macd地址是否匹配,ifcfg-enp8s0和ifcfg-enp7s0,
按照网络方法增加一行HWADDR=ipconfig查询到的对应网卡MAC地址;
c.重启network服务依旧报错;
3.通过GUI界面查看网络,提示“系统的网络服务与此版本的网络管理器不兼容”
这与之前停掉NetworkManager有关,此处不表;
4.因为ifcfg-enp7s0实际上没有插网线,修正其配置文件如下:
ONBOOT=no
重新启动服务后网络正常;
5.检查网络
1.network和NetworkManager不同,通过界面和通过配置文件,可能会导致配置混乱,且NetworkManager有些程序不支持,需要停用;
2.BOOTPROTO=none虽然可以表示静态ip,但是如果要启用,必须设置其为
BOOTPROTO=static或BOOTPROTO=dhcp
3.一个网卡没哟被启用,也就是没有设置动态ip或静态ip,是无法被初始化的,不能设置ONBOOT=yes
In Centos7.0 disabling NetworkManager will leave a dhcp client running configured for NetworkManager. This causes the error message RTNETLINK answers: File exists when the network service is started.
The stale dhclient process has the additional"benefit" that when the lease expires your dhclientwill choke, since it cannot reach NetWorkManager, thus removing your IP address.
If you grep for it, you will see that it points to a NetWorkManager configuration file.
[root@host~]# ps-ef| grep dhc
root 1865 792 0 Apr28? 00:00:00/sbin/dhclient-d-sf\
/usr/libexec/nm-dhcp-helper-pf/var/run/dhclient-eno1.pid-lf\
/var/lib/NetworkManager/dhclient-c96e56d3-a4c9-4a87-85ca-93dc0ca268f2-eno1.lease\
-cf/var/lib/NetworkManager/dhclient-eno1.conf eno1
So what you can do is kill the dhclient and only then start your network service.