samba、nfs服务、或者其他的硬盘、光盘挂载内容均可以把挂载信息写入到自动挂载的配置文件，/etc/fstab中，以实现开机自动挂载。
自动挂载简化了挂载工作，但是长时间不使用的资源挂载在服务器上，会占用带框、增加硬件负载。
autofs服务解决的问题就是：在需要使用硬盘等的资源时，才去自动进行挂载，避免不使用时挂载对资源的浪费。
下面实验在一台主机中完成，PC1主机。
1、在PC1主机中安装autofs
[root@PC1 ~]# yum install autofs.x86_64 -y Loaded plugins: langpacks, product-id, subscription-manager This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register. rhel7 | 4.1 kB 00:00 Resolving Dependencies --> Running transaction check ---> Package autofs.x86_64 1:5.0.7-40.el7 will be installed --> Processing Dependency: libhesiod.so.0()(64bit) for package: 1:autofs-5.0.7-40.el7.x86_64 --> Running transaction check ---> Package hesiod.x86_64 0:3.2.1-3.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ================================================================================ Package Arch Version Repository Size ================================================================================ Installing: autofs x86_64 1:5.0.7-40.el7 rhel7 550 k Installing for dependencies: hesiod x86_64 3.2.1-3.el7 rhel7 30 k Transaction Summary ================================================================================ Install 1 Package (+1 Dependent package) Total download size: 579 k Installed size: 3.6 M Downloading packages: -------------------------------------------------------------------------------- Total 78 MB/s | 579 kB 00:00 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : hesiod-3.2.1-3.el7.x86_64 1/2 Installing : 1:autofs-5.0.7-40.el7.x86_64 2/2 rhel7/productid | 1.6 kB 00:00 Verifying : hesiod-3.2.1-3.el7.x86_64 1/2 Verifying : 1:autofs-5.0.7-40.el7.x86_64 2/2 Installed: autofs.x86_64 1:5.0.7-40.el7 Dependency Installed: hesiod.x86_64 0:3.2.1-3.el7 Complete!
2、在PC1主机中修改主配置文件
[root@PC1 ~]# vim /etc/auto.master 1 # 2 # Sample auto.master file 3 # This is an automounter map and it has the following format 4 # key [ -mount-options-separated-by-comma ] location 5 # For details of the format look at autofs(5). 6 # 7 /media /etc/iso.misc ## /media为指定的挂载点， /etc/iso.misc为子配置文件 8 /misc /etc/auto.misc 9 # 10 # NOTE: mounts done from a hosts map will be mounted with the 11 # "nosuid" and "nodev" options unless the "suid" and "dev" 12 # options are explicitly given. 13 # 14 /net -hosts 15 # 16 # Include /etc/auto.master.d/*.autofs 17 # 18 +dir:/etc/auto.master.d 19 # 20 # Include central master map if it can be found using 21 # nsswitch sources. 22 # 23 # Note that if there are entries for /net or /misc (as …………
3、在PC1主机中编辑自配置文件
[root@PC1 ~]# vim /etc/iso.misc iso -fstype=iso9660,ro,nosuid,nodev :/dev/cdrom
## iso 为指定挂载点目录，文件系统类型光盘，光盘权限 ，将要挂载的目录
4、在PC1主机中查看挂载情况
[root@PC1 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/rhel-root 18G 3.0G 15G 17% / devtmpfs 985M 0 985M 0% /dev tmpfs 994M 140K 994M 1% /dev/shm tmpfs 994M 8.8M 986M 1% /run tmpfs 994M 0 994M 0% /sys/fs/cgroup /dev/sda1 497M 119M 379M 24% /boot /dev/sr0 3.5G 3.5G 0 100% /media/cdrom [root@PC1 ~]# ll -d /dev/cdrom lrwxrwxrwx. 1 root root 3 Dec 3 00:39 /dev/cdrom -> sr0 ## 说明光盘当前挂载状态
5、在PC1主机中启动autofs服务
[root@PC1 ~]# systemctl restart autofs [root@PC1 ~]# systemctl enable autofs.service ln -s '/usr/lib/systemd/system/autofs.service' '/etc/systemd/system/multi-user.target.wants/autofs.service' [root@PC1 ~]# df -h df: ‘/media/cdrom’: No such file or directory Filesystem Size Used Avail Use% Mounted on /dev/mapper/rhel-root 18G 3.0G 15G 17% / devtmpfs 985M 0 985M 0% /dev tmpfs 994M 140K 994M 1% /dev/shm tmpfs 994M 8.8M 986M 1% /run tmpfs 994M 0 994M 0% /sys/fs/cgroup /dev/sda1 497M 119M 379M 24% /boot /dev/sr0 3.5G 3.5G 0 100% /run/media/root/RHEL-7.0 Server.x86
6、 在PC1主机中进入/media目录查看
[root@PC1 ~]# cd /media/ [root@PC1 media]# df -h df: ‘/media/cdrom’: No such file or directory Filesystem Size Used Avail Use% Mounted on /dev/mapper/rhel-root 18G 3.0G 15G 17% / devtmpfs 985M 0 985M 0% /dev tmpfs 994M 140K 994M 1% /dev/shm tmpfs 994M 8.8M 986M 1% /run tmpfs 994M 0 994M 0% /sys/fs/cgroup /dev/sda1 497M 119M 379M 24% /boot /dev/sr0 3.5G 3.5G 0 100% /run/media/root/RHEL-7.0 Server.x86_64 [root@PC1 media]# ls [root@PC1 media]# cd iso [root@PC1 iso]# ls addons images Packages RPM-GPG-KEY-redhat-release EFI isolinux release-notes TRANS.TBL EULA LiveOS repodata GPL media.repo RPM-GPG-KEY-redhat-beta [root@PC1 iso]# df -h df: ‘/media/cdrom’: No such file or directory Filesystem Size Used Avail Use% Mounted on /dev/mapper/rhel-root 18G 3.0G 15G 17% / devtmpfs 985M 0 985M 0% /dev tmpfs 994M 140K 994M 1% /dev/shm tmpfs 994M 8.8M 986M 1% /run tmpfs 994M 0 994M 0% /sys/fs/cgroup /dev/sda1 497M 119M 379M 24% /boot /dev/sr0 3.5G 3.5G 0 100% /media/iso ## 当访问挂载点目录时，实现了自动挂载
以上实验实现了只有在使用硬盘资源时，能够实现自动挂载。