Please try -D dfs.block.size=4096000 The specification must be in bytes.
On Tue, May 5, 2009 at 4:47 AM, Christian Ulrik Søttrup <soett...@nbi.dk >wrote: - 隐藏引用文字 - > Hi all, > > I have a job that creates very big local files so i need to split it to as > many mappers as possible. Now the DFS block size I'm > using means that this job is only split to 3 mappers. I don't want to > change the hdfs wide block size because it works for my other jobs. > > Is there a way to give a specific file a different block size. The > documentation says it is, but does not explain how. > I've tried: > hadoop dfs -D dfs.block.size=4M -put file /dest/ > > But that does not work. > > any help would be apreciated. > > Cheers, > Chrulle > 2009/5/7 陈桂芬 <chenguifen...@163.com> > Hi: > > In my application, there are many small files. But the hadoop is designed > to deal with many large files. > > I want to know why hadoop doesn’t support small files very well and where > is the bottleneck. And what can I do to improve the Hadoop’s capability of > dealing with small files. > > Thanks. > >
