服务器镜像

什么是服务器镜像？

服务器镜像，顾名思义，就是将一台服务器上的所有数据和配置信息完整地复制到另一台服务器上的过程，这样，当原始服务器出现故障或者需要进行系统维护时，可以通过快速部署服务器镜像来实现快速切换，从而保证业务的连续性和稳定性。

服务器镜像的作用与优势

1、快速部署：通过服务器镜像，可以在短时间内完成服务器的部署，提高工作效率。

2、数据安全：服务器镜像可以确保数据的完整性和安全性，因为在创建镜像时，会将原始服务器上的所有数据和配置信息进行完整复制。

3、方便迁移：当需要将服务器从一个地理位置迁移到另一个地理位置时，可以使用服务器镜像来实现快速迁移，降低迁移风险。

4、灵活扩展：服务器镜像可以根据业务需求进行扩展，增加或减少资源，以满足不同场景的需求。

5、易于管理：通过服务器镜像，可以实现对多台服务器的管理，提高管理效率。

如何创建服务器镜像？

创建服务器镜像的方法有很多，这里以Linux系统的NFS(网络文件系统)为例进行介绍。

1、在原始服务器上安装NFS服务：

sudo apt-get install nfs-kernel-server

2、编辑NFS共享目录的权限：

sudo mkdir -p /var/nfs_share
sudo chown nobody:nogroup /var/nfs_share
sudo chmod 755 /var/nfs_share

3、在NFS共享目录下创建一个空文件，用于同步：

sudo touch /var/nfs_share/sync_file

4、在原始服务器上编辑/etc/exports文件，添加以下内容：

/var/nfs_share *(rw,sync,no_subtree_check)

5、重启NFS服务：

sudo systemctl restart nfs-kernel-server

6、在目标服务器上安装NFS客户端：

sudo apt-get install nfs-common

7、在目标服务器上创建一个挂载点：

sudo mkdir -p /mnt/nfs_share

8、在目标服务器上挂载NFS共享目录：

sudo mount -t nfs server_ip:/var/nfs_share /mnt/nfs_share

9、将同步文件复制到目标服务器：

sudo cp /var/nfs_share/sync_file /mnt/nfs_share/sync_file

10、在目标服务器上执行以下命令，使NFS共享生效：

sudo exportfs -a && sudo sync && sudo umount /mnt/nfs_share && sudo mount --bind /mnt/nfs_share /mnt/nfs_share && sudo service rpcbind restart && sudo service netadm restart && sudo service nfs restart && sudo mount -a && echo "1" > /proc/sys/vm/drop_caches && sync && echo "NFS Server Mirror is ready!" | wall & tail -f /dev/null & wait $! || exit $?; echo "NFS Server Mirror is ready!" | wall & tail -f /dev/null & wait $! || exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; exit $?; echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev/null & wait $! || echo "NFS Server Mirror has been stopped!" | wall & tail -f /dev\$1&wait %1 > \$222222222222222222222222222222222222222222&exit %1||echo "Error stopping NFS server mirror: \$1
Exiting with status code \$2"; kill $$ > \$333333333333333333333333333333333333333333&wait %1 > \$44444444444444444444444444444444444444444&exit %1||echo "Error stopping NFS server mirror: \$1
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