How to NFS mount the IP-STB software

In order to speed up development, KreaTV provides the possibility to let most of the boot image reside on a NFS mounted external disk instead of inside the IP-STB. To use this feature you need the following components:

• A rootdisk with the STB file system
• The correct DHCP options setup on the DHCP server
• A kernel image with NFS mount support
• A development STB

DHCP options

The DHCP options necessary for NFS mount is described in the DHCP options section.

Boot image with NFS mount support

Create an NFS kernel and a rootdisk as described in the Boot image building section.

1. Unpack the rootdisk in a suitable directory for the NFS server. It is important that the permissions are preserved on the rootdisk. Ensure this by unpacking it with tar xzpf <rootdisk file name>. Note that it unpacks into a directory called rootdisk.
2. Make sure your NFS server is setup to share your rootdisk at the location where you unpacked it. The /etc/exports file is used for this purpose. As an example, to share /my/nfs/exports/rootdisk, add the following line to the file:

   /my/nfs/exports/rootdisk *(rw,no_root_squash,no_subtree_check,sync,insecure,fsid=0)

   This will share the rootdisk with read and write permissions among other things. You will need to restart your NFS server for the changes to take effect. On later Fedora distributions, running sudo systemctl restart nfs.service works. On older Fedoras, run sudo service nfs restart instead.
3. Update your DHCP server to provide the address to the NFS server.
4. Update your DHCP server to provide the path to the root disk. The complete path should be stated. In this example it would be /my/nfs/exports/rootdisk/.
5. To pass NFS mount options just add the needed options together with the path separated with a comma character.
   • rsize - size of read packets
   • wsize - size of write packets
   • nfsvers - specifies which NFS version to be used
   • tcp - use TCP as protocol instead of default UDP
   Example:

   /my/nfs/exports/rootdisk/,rsize=4096,wsize=8192,nfsvers=3,tcp

6. If your nfs server uses nfs-version 4 (Fedora 18 and 19 use nfs-version 4 by default), you should change the nfs server setting by adding the following content in /etc/sysconfig/nfs (So that it can support nfs-versions 2 and 3). RPCNFSDARGS="--nfs-version 2,3"
7. If eth0 is not the network interface that communicates with the STB (for example, eth1 has the same netmask as the STB), then you should also enable the interface that you use in your firewall setting by using firewall configuration utilities or using the following command line: firewall-cmd --zone=trusted --add-interface=eth1
8. Make sure the STB downloads and starts the bootimage (kernel) with NFS support.
9. The kernel will mount the root file system via NFS and continue booting as normal.