Elasticsearch creating files but not releasing them until I restart the service

I am running elastcsearch 0.90.5 and recently I have been having issues with the disk running out of space. This is not caused by my indexes increasing in size but by the elasticsearch service holding on to the disk space.

If I restart the service the extra disk space is released and elasticsearch will start working again. The biggest issue with this is that in order to restart the service I have to take down the database.

Does anyone know what is causing this and how to fix it?

Thanks

Any chance you can try on a more recent version?

I am going to update to the newest version of 0.90.X in the next couple of weeks, but until then I want to make sure my database doesn't go down. Also If this is a problem in the new version I would like to know the cause.

Thanks

0.90.X is no longer supported, and it's almost 2 years old. You should upgrade anyway!

I know, but updating to 1.X or newer is a much larger project and I would like to get this fixed in the interim.

Thanks