automount

Automoun is another kind of NFS. The different is that in NFS mode the client need to connect to NFS server all the time. This will consume server resources making the server slow. But in automount mode, client dont have to connect to server all the time. When you access the nfs resource, the automount will run and mount the server resource. When you do not need the nfs resource, the automount will disconnect after some time.

Here is the steps to setup automount.

1. We have a nfs server. Which is sharing a directory. The server configure is the same as normal NFS server setting.

edit /etc/export content so that the server know which diretory to share and who can use the mount

[root@racnode1 temp]# cat /etc/exports
/opt/temp racnode2

start NFS service

[root@racnode1 temp]# service nfs start
Starting NFS services:  exportfs: No options for /opt/temp racnode2: suggest racnode2(sync) to avoid warning
                                                           [  OK  ]
Starting NFS mountd:                                       [  OK  ]
Stopping RPC idmapd:                                       [  OK  ]
Starting RPC idmapd:                                       [  OK  ]
Starting NFS daemon:                                       [  OK  ]
[root@racnode1 temp]#
[root@racnode1 temp]# showmount -e
Export list for racnode1:

2. do setting on client

edit /etc/auto.master which is the main mapping file. Autofs will mornitor the /opt/TempOnNode2. When access this directory, autofs will check the /etc/auto.home file to decide how to manage this mountpoint. When the directory is idle for 28second, It will automaticall umount.

[root@racnode2 opt]# cat /etc/auto.master
/opt/TempOnNode2      /etc/auto.home　　--timeout=28

Now edit /etc/auto.home.

[root@racnode2 opt]# cat /etc/auto.home
* -rw,no_root_squash,soft,intr 192.168.3.161:/opt/temp/&

Ok. Then we can startup the autofs service

[root@racnode2 TempOnNode2]# service  autofs start
Starting automount:                                        [  OK  ]

Then try to access /opt/TempOnNode2

[root@racnode2 dir1]# pwd
/opt/TempOnNode2/dir1
[root@racnode2 dir1]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_itiappgw1-lv_root
                       16G   15G   42M 100% /
tmpfs                1004M     0 1004M   0% /dev/shm
/dev/sda1             485M   31M  429M   7% /boot
192.168.3.161:/opt/temp/dir1
                       16G   15G   11M 100% /opt/TempOnNode2/dir1
[root@racnode2 dir1]#

You can see once we get into the directory /opt/TempOnNode2/dir1. The automount works and you can see the directory will umount after 28second.