Auto-mounting an NFS share using autofs

by Anish

Posted on Friday July 6

autofs is a program for automatically mounting directories on an as-needed basis. Auto-mounts are mounted only as they are accessed, and are unmounted after a period of inactivity. Because of this, automounting NFS/Samba shares conserves bandwidth and offers better overall performance compared to static mounts via fstab

autofs uses /etc/auto.master (master map) as its default primary configuration file.

Auto-mounting an NFS share

First Verify the NFS mount is accessiblle and available for mount

[root@]showmount -e 192.0.2.68
Export list for 192.0.2.68:
/mnt/nfsvol (everyone)

Install autofs

[root@]yum -y install autofs 
*       -rw     192.0.2.68:/mnt/nfsvol

Configuring user home directory in NFS share

Edit the file /etc/auto.master and create an indirect maps

[root@]cat /etc/auto.master
/home      /etc/auto.home

Edit/create the file /etc/auto.home and add automount location

[root@]cat /etc/auto.home
*       -rw     192.0.2.68:/mnt/nfsvol

Changes to the The Name Service Switch (NSS) configuration file, /etc/nsswitch.conf automount: files nis

start the autos service root@host-172-16-9-16 home]# systemctl start autofs

check the status of autofs service is running, you will be noticing lookupnssread_map: reading map file /etc/auto.home

Jul 06 04:27:07 host-172-16-9-16 automount[20523]: master_do_mount: mounting /home
Jul 06 04:27:07 host-172-16-9-16 automount[20523]: automount_path_to_fifo: fifo name /run/autofs.fifo-home
Jul 06 04:27:07 host-172-16-9-16 automount[20523]: lookup_nss_read_map: reading map file /etc/auto.home

Testing

Login to the client

[root@host-172-16-9-16 home]# ssh [email protected]
[email protected]'s password: 
Last login: Fri Jul  6 04:23:36 2018 from host-172-16-9-16

Check the pwd of the user it's mounted to the /home

-bash-4.2$ pwd
/home/test
-bash-4.2$ 

Check the df -kh the volume will be mounted

-bash-4.2$ df -kh 
Filesystem              Size  Used Avail Use% Mounted on
/dev/mapper/cl-root     6.2G  1.3G  5.0G  20% /
devtmpfs                908M     0  908M   0% /dev
tmpfs                   920M     0  920M   0% /dev/shm
tmpfs                   920M  8.5M  911M   1% /run
tmpfs                   920M     0  920M   0% /sys/fs/cgroup
/dev/vda1              1014M  181M  834M  18% /boot
tmpfs                   184M     0  184M   0% /run/user/0
192.0.2.68:/mnt/nfsvol  7.7G  128K  7.7G   1% /home/test

Troubleshooting Autofs

Enable logging, To do this, edit the file vi /etc/sysconfig/autofs and set LOGGING=debug and restart autofs service

All log message will be redirected to /var/log/messages

tail -f /var/log/messages
Jul  6 04:22:40 host-172-16-9-16 automount[20421]: mount_mount: mount(nfs): calling mkdir_path /home/test
Jul  6 04:22:40 host-172-16-9-16 automount[20421]: mount_mount: mount(nfs): calling mount -t nfs -s -o rw 192.0.2.68:/mnt/nfsvol /home/test
Jul  6 04:22:40 host-172-16-9-16 automount[20421]: spawn_mount: mtab link detected, passing -n to mount
Jul  6 04:22:40 host-172-16-9-16 automount[20421]: mount_mount: mount(nfs): mounted 192.0.2.68:/mnt/nfsvol on /home/test
Jul  6 04:22:40 host-172-16-9-16 automount[20421]: dev_ioctl_send_ready: token = 1
Jul  6 04:22:40 host-172-16-9-16 automount[20421]: mounted /home/test

Running automount in the foreground with verbose information

systemctl stop  autofs

Thanku for reading !!! Give a Share for Support

Your Support Matters!

Instead of directly asking for donations, I'm thrilled to offer you all nine of my books for just $9 on leanpub By grabbing this bundle you not only help cover my coffee, beer, and Amazon bills but also play a crucial role in advancing and refining this project. Your contribution is indispensable, and I'm genuinely grateful for your involvement in this journey!

Any private key value that you enter or we generate is not stored on this site, this tool is provided via an HTTPS URL to ensure that private keys cannot be stolen, for extra security run this software on your network, no cloud dependency