Hello, thanks for your help, I appreciate your hint. I think (reboot into the system with the fs mounted as root still outstanding), it fixed my problem. I read through the FAQ you mentioned, but I must admit, that I do not fully understand. What I am wondering about is, what caused this problem to arise. The filesystem was hardly a week old, never mistreated (powered down without unmounting or so) and not even half full. So what caused the data chunks all being allocated? The only thing that I could think of is that I created hourly snapshots with snapper. In fact in order to be able to do the balance, I had to delete something -so I deleted the snapshots. Can you tell me where I can read about the causes for this problem? Besides this: You recommend monitoring the output of btrfs fi show and to do a balance, whenever unallocated space drops too low. I can monitor this and let monit send me a message once that happens. Still, I'd like to know how to make this less likely. Greetings, Hendrik -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html