A method includes storing data encoded with an Error Correction Code (ECC) in analog memory cells, by buffering the data in a volatile buffer and then writing the buffered data to the analog memory cells while overwriting at least some of the data in the volatile buffer with success indications. Upon detecting a failure in writing the buffered data to the analog memory cells, recovered data is produced by reading both the volatile buffer and the analog memory cells, assigning reliability metrics to respective bits of the recovered data depending on whether the bits were read from the volatile buffer or from the analog memory cells, and applying ECC decoding to the recovered data using the reliability metrics. The recovered data is re-programmed.