Reading from and writing to a particular block

[Cagdas Gerede <ca...@gmail.com>]

I examined
org.apache.hadoop.dfs.DistributedFileSystem

For reads, I couldn't find a method to read a particular block or
chunk. I only see the open method, which opens an input stream for a
path.
How can I read only a specific block?

Also,
for writes, I cannot write to a particular block. I have to write the
entire file again to modify a single byte. Am I correct?


Thanks for your responses,
Best,

Cagdas