/** An FSDataset has a directory where it loads its data files. */ public FSDataset(DataStorage storage, Configuration conf) throws IOException { this.maxBlocksPerDir = conf.getInt("dfs.datanode.numblocks", 64); FSVolume[] volArray = new FSVolume[storage.getNumStorageDirs()]; for (int idx = 0; idx < storage.getNumStorageDirs(); idx++) { volArray[idx] = new FSVolume(storage.getStorageDir(idx).getCurrentDir(), conf); } volumes = new FSVolumeSet(volArray); volumeMap = new HashMap<Block, DatanodeBlockInfo>(); volumes.getVolumeMap(volumeMap); registerMBean(storage.getStorageID()); }