I recently came to know about HDFS Snapshots, I know that HDFS Snapshot are readonly copy of Name node metadata and any accidentally deleted file can be recovered from HDFS Snapshots. Can someone please explain how HDFS Snapshots internally work and any criteria on maximum duration within which a deleted file has to be recovered from HDFS Snapshots? Assuming HDFS Snapshot is take before deletion of the file, can I recover a file which is deleted few weeks back from HDFS Snapshot? If yes what if memory blocks of deleted file is used to store data of new file, before the recovery of deleted file.
Please let me know if something is not clear.