Mac OS X ._ files reek havoc on OH2

Over the past few days i’ve been working on migrating my OH1 RP2 install to my new Pine64 Ubuntu 16.04 OH2 setup.
After tackling some major hurdles i was left with a system to showed crazy erratic behaviour.

A few examples:

  • Rules would work but stop working all of a sudden
  • Openhab.log would show Null Pointer exceptions for rules triggering
  • Openhab.log would show “Group AND needs 2 arguments…using equality.”
  • Openhab.log would show complain about Rule parsing and their syntax.

In my quest to solve my various challenges in my OH2 setup, i copied files (rules, items, PNG) back and forth between OH2 and my Macbook using a samba share on OH2 and the Macbook finder application.

When using Mac OS X finder to copy and create files, ._xxx.x files are created to store file information about the actual file.
Creating/Copying a file called test.rules would also create a file called ._test.rules

According to Openhab.log these files are also loaded and refreshed with every change.

After i found a ._ for almost every file i made or copied into my OH2 setup i decided to find out if these files were the root cause for all of my troubles with my OH2 setup.

I removed them all… restarted the OH2 service… et voila… 0…but i mean 0 errors in Openhab.log… all rules firing and no more erratic behaviour!!!

Ofcourse i’m over the moon and filled with joy now i have a smooth OH2 setup running… but i’ve used this method of moving files between my Mac and OH1 for quit some time now… this has never caused me any issues.

Does anybody know why or how this causes strange things to happen in OH2?


Well, probably because they are not recognized as files that should be ignored and as they end with .items, .rules, etc. they are tried to be parsed.
It probably makes a lot of sense to exclude any file starting with a dot from processing. Might I ask you to enter an issue about that at Thanks!

Yes i will do so right away.