Difference between revisions of "Network File System configuration"

Latest revision as of 12:17, 1 February 2022

Introduction

On this page, you will find usefull informations to configure NFS (Network File System) on your Host and your Target.

NFS server on your development Host

Installation

• On Fedora, NFS is part of your distribution so you normally don't need to install it.
• On Ubuntu/Kubuntu:

$ sudo apt-get install nfs-kernel-server

• On OpenSUSE:

$ sudo zypper install yast2-nfs-server

• On Gentoo:

# emerge -av nfs-utils

You can also take a look at the gentoo wiki

Configuration

/etc/exports

• You have to declare the directory where you're going to store the files you want to share accross the network. For that you have to modify the /etc/exports file with (for example):

$ sudo vim /etc/exports

and add it (at the end of the file):

...
# Directory for Armadeus:
/local/export     192.168.0.0/255.255.255.0(ro,no_root_squash,sync)
...

In that case your Host will authorize all client from the subnet 192.168.*.* to access /local/export in read only mode. If you want read/write access from your APF to your exported dir, then replace ro with rw.

• In order to use the same folder through TFTP and NFS, using the default U-Boot scripts for example, it recommended to export your /tftpboot folder as well:

...
# Directory for Armadeus:
/local/export     192.168.0.0/255.255.255.0(ro,no_root_squash,sync)
/tftpboot     192.168.0.0/255.255.255.0(ro,no_root_squash,sync)
...

• If not existing, create your export directory (for example):

$ sudo mkdir -p /local/export
$ sudo chown -R $USER:$GROUP /local/export/

/etc/hosts

• You have to declare your APF/OPOS board in the PC hosts list, to fully support NFS access from U-Boot. For such purpose you have to update the /etc/hosts file with your preferred editor (as root):

$ sudo vim /etc/hosts

and add the IP address of your board after the localhost definition for example :

127.0.0.1	localhost
192.168.0.10	apf
...

Restart of NFS server

 # /sbin/service nfs restart

 # /sbin/service nfs status

 # /sbin/service nfs start

 $ sudo /etc/init.d/nfs-kernel-server restart

 # /etc/init.d/nfsserver restart

 # /etc/init.d/nfs restart

NFS usage on your Armadeus board

Mount the NFS partition manually

• check if mount point is existing (for example we will take /mnt/nfs):

# ls /mnt

• if not existing, create the mount point:

 # mkdir -p /mnt/nfs

• mount it (for example):

 # mount -t nfs 192.168.0.2:/local/export /mnt/nfs

Here 192.168.0.2 is your Host IP address and /local/export the name of your Host directory you want to mount.

Note: On some nfs server (for exemple with debian wheezy) there is a warning when we mount nfs partition. But the filesystem is mounted : # mount /mnt/nfs/ svc: failed to register lockdv1 RPC service (errno 97).

Mount the NFS partition automatically at each boot from FLASH

• login to your Armadeus board as root
• open the /etc/fstab file and add this line:

<host-ip>:/<path-to-shared-folder> /mnt/<path-to-mount-folder> nfs hard,intr,rsize=8192,wsize=8192 0 0

example:

192.168.0.2:/local/export /mnt/nfs nfs hard,intr,rsize=8192,wsize=8192 0 0

• check your modification:

 # mount /mnt/nfs

• reboot your board

 # reboot

• and enjoy the result

 # df
 # ls /mnt/nfs

When you have a problem, verify that the NFS server is running on the host:

 $ /sbin/service nfs status

 $ /etc/init.d/nfs-kernel-server status

Boot from NFS

This boot procedure is usefull to test a modified rootfs and/or a linux kernel keeping safe the original flash memory content of your board.

• on your Host, expand generated rootfs image to your NFS export dir (for example if your NFS export dir is /tftpboot on your Host) and you want to boot on it using the U-Boot script nfsboot:

 $ make shell_env
 $ source armadeus_env.sh
 $ sudo mkdir -p /tftpboot/$ARMADEUS_BOARD_NAME-root/boot
 $ sudo tar xvf $ARMADEUS_ROOTFS_TAR -C /tftpboot/$ARMADEUS_BOARD_NAME-root

• The copy of the Linux kernel to the NFS /boot folder, makes possible to also download it with NFS when booting the board:

 $ sudo cp $ARMADEUS_BINARIES/$ARMADEUS_BOARD_NAME-linux.bin /tftpboot/$ARMADEUS_BOARD_NAME-root/boot/

• With recent (3.10+) kernels, you also have to copy the Device Tree blobs:

 $ sudo mkdir -p /tftpboot/$ARMADEUS_BOARD_NAME-root/boot/dtbs
 $ sudo cp $ARMADEUS_BINARIES/*.dtb /tftpboot/$ARMADEUS_BOARD_NAME-root/boot/dtbs/

• On your board, in U-Boot, check if the rootpath envt variable is set accordingly:

 BIOS> printenv rootpath

• If not, then set it (by default U-boot is configured to use the following path /tftpboot/apfXXXX-root) where apfXXXX may be apf9328, apf27, apf28, apf51, apf6:

 BIOS> setenv rootpath /tftpboot/${board_name}-root

• save it:

 BIOS> saveenv

• then boot with:

 BIOS> run nfsboot

Summary of the required Packages:

• portmap (Buildroot)
• nfs (busybox)
• nfs support (Linux, activated by default in Armadeus configuration)

Troubleshooting

RPC: Program not registered

• If nfsd and mountd daemons are not running on your Host, then you will get a message like:

mount: RPC: Program not registered

• In that case, restart the NFS service on your Host (see above).

Portmap/RPCbind

• To successfully mount a NFS drive, portmap/rpcbind daemon should be running on your APF/OPOS, if not, system will hang during some minutes when you launch the mount !!

To check if portmap/rpcbind is running, look at the running processes:

 # ps faux

If portmap/rpcbind is not listed, then launch it manually or install it:

* Note: ''portmap'' is obsolete since 2017

===Connection refused===
* If you get this on your APF when trying to mount:
<pre class="apf">
mount: mounting 192.168.0.2:/local/export on /mnt/nfs/ failed: Connection refused

• then your kernel might need some extra options:

mount -o port=2049,nolock,proto=tcp 192.168.0.2:/local/export /mnt/nfs/

Kernel debug

• If none of the above workarounds was successful -> no luck ! :-) You can still activate NFS debugging by recompiling your kernel with CONFIG_SUNRPC_DEBUG options and use setenv extrabootargs nfsrootdebug in U-Boot. And then you dig...

NFS Server under Windows

For those who want to use the NFS service on Windows, a small and FREE NFS server is available here.

Links

• http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.8.