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The case of HDFS paths that are not mapped to any MapR-FS volumes

Question asked by Wibe2017 on Nov 28, 2017
Latest reply on Nov 28, 2017 by cathy



I am relatively new to MapR, and I am still learning basic concepts that MapR-FS covers.


I am aware of the concept of volumes and the details of how to create them, and to use them in order to better manage the data. I know as well the volumes are exclusive to MapR and do not make part of HDFS.


My question is, how does MapR-FS manage the HDFS directories that are not mapped to any MapR volumes?


If I have an HDFS path named '/a' .. which is not a mount path to any MapR FS volume, neither any of the sub-paths of '/a' ... so how the data contained in this path is handled by MapR-FS. 


Lot of questions come in my mind :

  • How this data is secured?
  • How this data is replicated?
  • Can one create data outside of MapR-FS volumes?
  • Is there a default volume for this kind of situation?
  • What is the topology of the data that is outside of volumes?
  • Who is the Accountable Entity of this data?
  • ... etc


Thanks in advance.


Best regards.