apache/hadoop · error · IOException

Unknown inode type: numBlocks={}

Error message

Unknown inode type: numBlocks={}

What it means

Error "Unknown inode type: numBlocks={}" thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImageFormat.java:879

      
      final boolean isWithName = in.readBoolean();
      // lastSnapshotId for WithName node, dstSnapshotId for DstReference node
      int snapshotId = in.readInt();
      
      final INodeReference.WithCount withCount
          = referenceMap.loadINodeReferenceWithCount(isSnapshotINode, in, this);

      if (isWithName) {
          return new INodeReference.WithName(null, withCount, localName,
              snapshotId);
      } else {
        final INodeReference ref = new INodeReference.DstReference(null,
            withCount, snapshotId);
        return ref;
      }
    }
    
    throw new IOException("Unknown inode type: numBlocks=" + numBlocks);
  }

    /** Load {@link INodeFileAttributes}. */
    public INodeFileAttributes loadINodeFileAttributes(DataInput in)
        throws IOException {
      final int layoutVersion = getLayoutVersion();
      
      if (!NameNodeLayoutVersion.supports(
          LayoutVersion.Feature.OPTIMIZE_SNAPSHOT_INODES, layoutVersion)) {
        return loadINodeWithLocalName(true, in, false).asFile();
      }
  
      final byte[] name = FSImageSerialization.readLocalName(in);
      final PermissionStatus permissions = PermissionStatus.read(in);
      final long modificationTime = in.readLong();
      final long accessTime = in.readLong();
  
      final short replication = namesystem.getBlockManager().adjustReplication(

View on GitHub (pinned to 2add963021)

Solutions

1. The image contains an unrecognized inode entry; restore from a valid fsimage or investigate image corruption.

When it happens

Trigger: Loading an old fsimage inode entry whose numBlocks value matches neither a file nor a directory nor a symlink.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/1524de2ec5172ba7. Report an issue: GitHub.