Hi, Generally the user expectation is to get back to the previous state of FileSystem, so we should see the old state of block(the block size should shrink). I couldn't find the semantics of this kind of operations in design document either.
Thank You Pushparaj On Tue, Oct 21, 2014 at 8:23 PM, Andrew Wang <andrew.w...@cloudera.com> wrote: > Hi Pushparaj, > > Based on those steps, isn't the expectation that you end up with a 0.6*size > block at the end? Blocks are append only (i.e. only grow in length), so > deleting a snapshot cannot result in a block shrinking. > > Best, > Andrew > > On Tue, Oct 21, 2014 at 7:20 AM, Pushparaj Motamari <pushpara...@gmail.com > > > wrote: > > > Hi, > > > > Consider the scenario below. > > > > /A/file.txt in HDFS > > > > 1. file.txt size = 0.5*(Size of Block). > > > > 2. Take Snapshot on directory A > > > > 3. Append to the file.txt, making its size as 0.6*(Size of Block) > > > > 4. Remove/delete the snapshot on folder taken in step2. > > > > My Question > > -------------------------------- > > 1. How does HDFS handle when it has to decrease the size of block, as > above > > when we delete the snapshot the block size has to be reduces to its > > previous size. This code is handled at datanode or Namnode? > > > > Thank You > > >
