Exact meaning of NFS errorcode -110

Question

Hy community,

I want to boot the rootFS of my targetboard via NFS but the bootlog always prints the error "NFS: failed to create MNT RPC client, status=-110". Does anybody know what this code exactly means or where I can look it up?

I have already done:

• enabled everything related to NFS,Root-FS etc. in the kernel-config
• my firewall is inactive, iptables set to ACCEPT for Input,Output and Forwarding
• exported the nfs-directory in etc/exports and saved it afterwards
• checked that service nfs-kernel-server is running
• checked that every folder in path/to/nfsroot has every right ( chmod 777)
• rpcinfo on host verifies running nfs
• versions on nfs-server and client are the same
• mounted nfs-directory on targetboard (=client)
• pinging the server to verify that ethernet-connection is up

Thank you in advance.

Answer 1

The NFS client here uses the standard return value mechanism within the kernel. That means that error values are returned as the negative of the appropriate errno value. In your case, that is 110, or ETIMEDOUT.

Now, as to why you're getting a timeout, I can't say. Getting an NFS root working can be challenging to troubleshoot. It seems likely that there is some problem with the kernel networking "autoconfiguration" process. You need to be sure that the correct network driver is getting loaded, the interface is getting an IP address configured, and so forth.

If you haven't already seen it: https://www.tldp.org/HOWTO/NFS-Root.html

Answer 2

Use the showmount -e command and make sure your NFS directory is there.

When I set up NFS for my beaglebone, I had to make changes to bootargs using setenv in the u-boot prompt. More specifically this:

setenv bootargs 'console=ttyO0,115200n8 noinitrd ip=192.168.0.10:255.255.255.0 earlyprintk root=/dev/nfs. rw nfsroot=192.168.0.23:/home/gabe/Desktop/BBNFS2/rootfs rootfstype=ext4 rootwait'

Hope it helps.