// stop the previous writer before check a replica's length
long replicaLen = replicaInfo.getNumBytes();
if (replicaInfo.getState() == ReplicaState.RBW) {
ReplicaBeingWritten rbw = (ReplicaBeingWritten)replicaInfo;
// kill the previous writer
rbw.stopWriter();
rbw.setWriter(Thread.currentThread());
// check length: bytesRcvd, bytesOnDisk, and bytesAcked should be the same
if (replicaLen != rbw.getBytesOnDisk()
|| replicaLen != rbw.getBytesAcked()) {
throw new ReplicaAlreadyExistsException("RBW replica " + replicaInfo +