Achilleas Mantzios <achill@xxxxxxxxxxxxxxxxxxxxx> writes: > Remember : postgresql checkpointer decided to remove 5000+ files before shutdown. If any conditions were keeping those files afloat should also hold at this point, right. > The question is why didn't Postgresql removed them earlier. WAL files get removed/recycled after completion of a checkpoint. So apparently, checkpoints were not finishing during normal operation, but the shutdown checkpoint managed to terminate normally. That eliminates a lot of the usual theories about why checkpoints might not be succeeding (like a dirty buffer that always fails to be written, say as a result of broken permissions on its file). The only theory that comes to mind is that the checkpointer process was stuck somehow, but just "soft" stuck, in a way that allowed the postmaster's time-to-shut-down-please signal to unstick it. No, I have no idea how that could happen exactly. If it happens again, it'd be really interesting to attach to the checkpointer with a debugger and collect a stack trace. regards, tom lane
