怎么办linux启动不起来升级glibc导致CentOS启动不了卡住启动画面紧急补救恢复数据

前段时间更新glibc版本，把/usr/lib64/libc-2.12.so & libc.so.6 -> libc-2.12.so 这个软连接更改之后导致报错：

    ls: error while loading shared libraries: libc.so.6: cannot open shared object file: No such file or directory

    无法远程登录，终端也无法登录，也无法单用户登录，如图：

nano   /mnt/sysimage/etc/sysconfig/selinux

ldconfig -l -v /lib64/libc-2.12.so

/opt/modules/flume/bin/flume-ng agent –conf conf/ –name a1 –conf-file job/flume-telnet-logger.conf -Dflume.root.logger=INFO,console

alias  "flume"="/opt/modules/flume/bin/flume-ng agent –conf conf/ –name a1 –conf-file job/flume-telnet-logger.conf -Dflume.root.logger=INFO,console"

chroot /mnt/syimage/

telnet localhost 44444

最终版本：

echo  $LD_LIBRARY_PATH

export LD_LIBRARY_PATH=/usr/lib64/:$LD_LIBRARY_PATH

export LD_LIBRARY_PATH=/opt/soft/gc/glibc-2.17/lib:$LD_LIBRARY_PATH

export LD_LIBRARY_PATH=/opt/soft/gc/glibc-2.17/lib:$LD_LIBRARY_PATH

strings /lib64/libc.so.6 | grep GLIBC

ls  -l   /lib64/libc.so.6

ln -sf /opt/soft/gc/glibc-2.17/lib/libc-2.17.so  /lib64/libc.so.6

ln -sf /usr/lib64/libc-2.12.so  /lib64/libc.so.6

ls  -l   /lib64/libc.so.6

[root@vir-centos7 ~]# mkdir /tmp/myroot/lib64 -p

[root@vir-centos7 ~]# cp /lib64/libtinfo.so.5 /tmp/myroot/lib64/

[root@vir-centos7 ~]# cp /lib64/libdl.so.2 /tmp/myroot/lib64/

[root@vir-centos7 ~]# cp /lib64/libc.so.6 /tmp/myroot/lib64/

[root@vir-centos7 ~]# cp /lib64/ld-linux-x86-64.so.2 /tmp/myroot/lib64/

[root@vir-centos7 ~]# chroot /tmp/myroot

/opt/soft/gc/glibc-2.17/build

恢复：

export LD_PRELOAD=/lib64/libc-2.12.so

[root@CentOSA lib64]# ldconfig

export LD_LIBRARY_PATH=/lib64:$LD_LIBRARY_PATH

cp /usr/glibc-2.17/lib/libc-2.17.so /lib64/libc-2.17.so 

libc-2.17.so

ln -s /lib64/libc-2.17.so /lib64/libc.so.6

/opt/soft/gc/glibc-2.17/build

$((expression))

$[expression]

expr expression

出现错误：  chroot:  failed  to  run  command  '/bin/sh'  : No  such  file  or  directory

ldd /mnt/vh2/bin/bash