question Re: How HDFS Snapshot works internally. in Support Questions

How HDFS Snapshot works internally.

vinayraghava198 — Thu, 16 Mar 2017 15:26:00 GMT

Hi All,

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.

Re: How HDFS Snapshot works internally.

namaheshwari — Thu, 16 Mar 2017 23:20:36 GMT

Hi @Vinay R - Can you please close this question. I think you accidentally asked the same question twice:

https://community.hortonworks.com/questions/89165/how-hdfs-snapshot-works-internally-1.html

Re: How HDFS Snapshot works internally.

vinayraghava198 — Tue, 21 Mar 2017 13:37:33 GMT

This is duplicate of the below question so closing this question.

https://community.hortonworks.com/questions/89165/how-hdfs-snapshot-works-internally-1.html#answer-89207