diff --git a/src/java/org/apache/cassandra/db/commitlog/CommitLogAllocator.java b/src/java/org/apache/cassandra/db/commitlog/CommitLogAllocator.java
index 963e41e83c..0359c5817a 100644
--- a/src/java/org/apache/cassandra/db/commitlog/CommitLogAllocator.java
+++ b/src/java/org/apache/cassandra/db/commitlog/CommitLogAllocator.java
@@ -101,6 +101,7 @@ public class CommitLogAllocator
                         // almost always a segment available when it's needed.
                         if (availableSegments.isEmpty() && (activeSegments.isEmpty() || createReserveSegments))
                         {
+                            logger.debug("No segments in reserve; creating a fresh one");
                             createFreshSegment();
                         }
                     }
@@ -156,6 +157,8 @@ public class CommitLogAllocator
             discardSegment(segment, true);
             return;
         }
+
+        logger.debug("Recycling {}", segment);
         queue.add(new Runnable()
         {
             public void run()
@@ -205,6 +208,7 @@ public class CommitLogAllocator
      */
     private void discardSegment(final CommitLogSegment segment, final boolean deleteFile)
     {
+        logger.debug("Segment {} is no longer active and will be deleted {}", segment, deleteFile ? "now" : "by the archive script");
         size.addAndGet(-DatabaseDescriptor.getCommitLogSegmentSize());
 
         queue.add(new Runnable()
diff --git a/src/java/org/apache/cassandra/db/commitlog/CommitLogSegment.java b/src/java/org/apache/cassandra/db/commitlog/CommitLogSegment.java
index 2ee90adf86..0449c47941 100644
--- a/src/java/org/apache/cassandra/db/commitlog/CommitLogSegment.java
+++ b/src/java/org/apache/cassandra/db/commitlog/CommitLogSegment.java
@@ -100,8 +100,9 @@ public class CommitLogSegment
 
                 if (oldFile.exists())
                 {
-                    logger.debug("Re-using discarded CommitLog segment for " + id + " from " + filePath);
-                    oldFile.renameTo(logFile);
+                    logger.debug("Re-using discarded CommitLog segment for {} from {}", id, filePath);
+                    if (!oldFile.renameTo(logFile))
+                        throw new IOException("Rename from " + filePath + " to " + id + " failed");
                     isCreating = false;
                 }
             }
@@ -110,9 +111,7 @@ public class CommitLogSegment
             logFileAccessor = new RandomAccessFile(logFile, "rw");
 
             if (isCreating)
-            {
-                logger.debug("Creating new commit log segment " + logFile.getPath());
-            }
+                logger.debug("Creating new commit log segment {}", logFile.getPath());
 
             // Map the segment, extending or truncating it to the standard segment size
             logFileAccessor.setLength(DatabaseDescriptor.getCommitLogSegmentSize());