Nfs exports oddity

I’ve just installed Rockstor on an HP Proliant microserver (gen 8). Dual core AMD Turion, 2 GB RAM, a 160 GB system drive and a 1 TB storage drive. Rockstor replaces a custom Slackware install (the original system drive failed)

At the moment, the storage drive is a single partition, formatted as EXT4 (I might move it to BTRFS in the future, but I’ve currently no space to put the existing data during any such move).

Install was fine. I do wonder why Plymouth is installed - seems a bit of a waste on what is normally going to be a text-mode or headless machine.

I use both Samba and NFS on the Rockstor box. It is used both as general file storage and as a backup for a Linux gateway/mail server machine. When that machine backs up, it uses an NFS mount. /etc/exports on the Rockstor machine is as follows:

That works fine. However, twice since I’ve set the machine up (which was about 8 hours ago), I’ve found that /etc/exports has been left as a zero-length file. I’ve not found any log entries that seem to relate, and I’ve never seen this sort of problem before.

Anyone have any ideas what could cause this, or even where I might look to find clues?