@firefishy: thanks for the ulimit suggestion. Unfortunately I couldn't (easily) get it to work on Debian 7. @RomanZ: great you're already working on a fix! However, I really want to be able to trust my precious files to btsync. If other users mention files disappearing or getting overwritten by older revisions, combined with my own experience with the open files issue, I'm getting worried. Can you tell us anything to give us some peace of mind? For example, do the developers have a good regression testing suite? ps. I should add that I'm very happy you do support Linux.