Tuesday, July 27, 2010

Quick NFS-setup

Making a NFS-server is done in two steps. Setting up the server and then starting it.

1.1 Configurating the server

The files to edit is placed in the /etc folder.
We are going to edit the exports-, hosts.deny- and the hosts.allow-file.
The /etc/exports contains information on what dirrectories you share and what permitions the clients have. Use an editor to edit the file and add a line with the following format:
directory mashine1(option11, option12) machine2(option21, option22)...
The options should be “ro”(read only) or “rw”(read/write). Also add a option called “no_root_squash”.
A line could look like this:
/home 192.168.0.(ro,no_root_squash),no_root_squash)
Instead of the 192.168.0. which is a wildcard you can write:
The /etc/hosts.deny contain information on which deamons the clients are denied to access. Insert a line which sais
This makes ALL the protocols unavailable for ALL the users.
The /etc/hosts.accept contain information on which deamons the clients are allowed to access. Insert the following lines:
portmap: [client-ip or name]
   lockd:   [client-ip or name]
   rquotad: [client-ip or name]
   mountd:  [client-ip or name]
   statd:   [client-ip or name]
And that should complete the server setup.

1.2 Starting the server

Newer releases should start the NFS at startup. Check if it’s already running by running “# rpcinfo -p”. This should show something like this:
program vers proto port
   100000 2 tcp 111 portmapper
   100000 2 udp 111 portmapper
   100011 1 udp 749 rquotad
   100011 2 udp 749 rquotad
   100005 1 udp 759 mountd
   100005 1 tcp 761 mountd
   100005 2 udp 764 mountd
   100005 2 tcp 766 mountd
   100005 3 udp 769 mountd
   100005 3 tcp 771 mountd
   100003 2 udp 2049 nfs
   100003 3 udp 2049 nfs
   300019 1 tcp 830 amd
   300019 1 udp 831 amd
   100024 1 udp 944 status
   100024 1 tcp 946 status
   100021 1 udp 1042 nlockmgr
   100021 3 udp 1042 nlockmgr
   100021 4 udp 1042 nlockmgr
   100021 1 tcp 1629 nlockmgr
   100021 3 tcp 1629 nlockmgr
   100021 4 tcp 1629 nlockmgr
If not, simply run the following commands in the following order: “rpc.portmap”, “rpc.mountd”, “rpc.nfsd”, “rpc.statd”, “rpc.lockd”, “rpc.rquotad”.
Add the commands to /etc/rc.local to make them permanent.
This should start the correct deamons. Now run the “# rpcinfo -p” again and check the table.
Now export your filesystem by typing: “# exportfs -ra”, check it by runnning “# showmount -e [ip-adresse]“.

2. NFS-client

Simlply add the following line in /etc/fstab:
# device      mountpoint       fs-type    options dump fsckorder
   [hostip]:[folder] [folder] nfs rw,hard,intr 0 0
   linux.uib.no:/home/ /home/linux/ nfs rw,hard,intr 0 0
The upper line is just a desctiption and does not need to be added, though it’s smart to add it to the top of the table.
Write “# mount -a” to remount all the lines in fstab. Now see if you can access the mount point. You should be able to access it at this point. For permanent mounting… Edit the /etc/rc.local. Add the following line:
mount -a
This run the commando mount -a at the end of your boot sequence.
Now your nfs should work!
For troubleshooting, FAQs and more detailed descripitons read theNFS-HOWTO here.
And remember to check your firewall!