When we manual mount the NFS and SMB file system, it will not available persistently. The mount point will be lost once you reboot the system. To mount the remote file system (NFS and SMB) persistently, you can configure the system automatically mount the remote file system edit /etc/fstab file.
As an alternative to use /etc/fstab, you can configure automount to mount the share automatically. Automount can be used for SMB as well as NFS mount. Automount is implemented by the autofs servie that take care of mounting a share when an attempt is made or on demand, and it will automatically unmount the share when no longer in used. One of the benefit of automounter, user do not need to have root privileges to run the mount and umount command.
Configuring an automount is a multiple step process.
First step, you need to install the autofs package by enter following command
yum install -y autofs
Second step, you need to edit the master configuration file /etc/auto.master or add a master map file (file must have an extension of .autofs) to /etc/auto.master.d directory. This configuration files will define the base directory used for mount point and identify the mapping file used for creating the automounts.
In this example, i going to add a master map file
vim /etc/auto.master.d/avms3.autofs
Syntax of master map file
Mount Point Map Files
Mount Point – Location or folder where to mount the autofs file system
Map File – Name of the map source to use for mounting
Indirect Map
An indirect map uses a substitution value of a key to establish the association between a mount point on the client and a directory on the server. Substitution value is the pathname to create virtual directory
/cifs /etc/auto.master.d/indirect_auto.cifs
note: /cfs directory will auto create once autofs service is start
Now you have to add/edit the mapping file that you specified on above step. Each mapping file consist of the mount point, mount options, and the source location to mount
vi /etc/auto.master.d/indirect_auto.cifs
Sample configuration of mapping file
data1 -fstype=cifs,rw,credentials=/etc/auto.master.d/sdrc.txt ://30.30.9.245/demosdplt
data1 -> mount point – will auto create and remove by autofs service
-fstype -> is the file system type, example: nfs, cifs,xfs and etc
credentials -> specific the credential file location. Note: in this example, i will put cifs username and password in this credential file.
Example of credentials file (/etc/auto.master.d/sdrc.txt)
username=user
password=abc123
Source share location -> in this example is the cifs share path
Indirect Wildcard map
If you have a directory with subdirectories, automounter can be configured to access any one of the those directories using a single mapping file.
Sample configuration of mapping file
* -fstype=cifs,rw,credentials=/etc/auto.master.d/sdrc.txt ://30.30.9.245/demosdplt/&
* -> asterisk character is the mount point
& -> subdirectory if the source location
Direct Map
Direct maps are used to map the share to an existing absolute path mount point
/- /etc/auto.master.d/direct_auto.cifs
Sample configuration of mapping file
/avms3 -fstype=cifs,rw,credentials=/etc/auto.master.d/sdrc.txt ://30.30.9.245/demosdplt
avms3 -> absolute path. If avms3 is an existing directory, it will mount on it. Else, you have to create the directory to allow autofs to mount share location
-fstype -> is the file system type, example: nfs, cifs,xfs and etc
credentials -> specific the credential file location. Note: in this example, i will put cifs username and password in this credential file.
Example of credentials file (/etc/auto.master.d/sdrc.txt)
username=user
password=abc123
Source share location -> in this example is the cifs share path
Last Steps – Start and enable the automounter service.
systemctl start autofs
systemctl enable –now autofs
Test AutoFS
A) Indirect map
i. Verify cifs directory is auto created by autofs
ii. verify the share folder is link to data1
B) Direct map
i. Verify /avms3 directory is automount cifs share
Debugging AutoFS
Enable the debug log by adding LOGGING=”debug” in /etc/sysconfig/autofs
Debugging log will show at /var/log/messages