NFS started to malfunction all of a sudden; "shutdown" throws segmentation fault
 

Hi,
I've been using a MityDsp-L138F SoM (featuring TI's OMAPL138 processor) with NFS. My host PC has a virtual machine with Ubuntu 16.04 installed, and I've been exporting a directory as NFS to the device without issues.

Last week, either the kernel or the file system started behaving unexpectedly, so I deleted the file system from the host side, and restarted with an untouched version supplied by the manufacturer.

However, since then, things have become even messier. When I login as "root" on the device, the terminal prints "@mityomapl138:/home/root#" (it used to be something like "root@mityomapl138:~#").

And I can't issue commands like "shutdown" or "reboot", either; doing so throws a segmentation fault error.

I have no idea what I did wrong. Have any of you guys encountered such a problem?

Thanks in advance.
OkCalis

Edit: I'm now sure that the issue stems from the Ubuntu host, not the embedded device, as it works as expected on another NFS server computer. But I don't know how I can fix it.

As I suspected, the host side was causing the problem. Somehow, the permissions of the root file system directory in /export were reset.
This solved the problem. I don't know if the -R (recursive) option is necessary, though.