MapR loopbacknfs POSIX Client

The MapR POSIX Client feature allows app servers, web servers, and other client nodes and apps to read and write directly to a MapR cluster. Starting with the 4.0.2 release, MapR provides single-user loopbacknfs licenses that give access to one or more clusters.

The table below summarizes the differences between the basic Linux OS NFS client and the MapR POSIX client:
Linux OS Client MapR POSIX Client
Client OS
  • Supported Linux distributions and desktop systems (Mac OS X and Windows)
  • Supported Linux distributions only
  • No version for Mac OS X
Installs On Node Type
  • Client node - not part of MapR cluster
  • No mapr-fileserver or other Hadoop services
  • Client node
  • Cluster node
Access to Cluster
  • Must have direct network access to all MapR cluster nodes
  • Same
Supported Interfaces
  • Apache HDFS and MapR Filesystem
Connection to File System
  • Point to point
  • Via an NFS gateway
  • Single point of failure
  • Proxied on host to regular MapR client traffic
  • Direct, no NFS gateway
  • No single point of failure
  • Link to NFS gateway is insecure
  • Fully secured

The Linux OS NFS client must go through an NFS gateway, the link to the gateway is not secured, and transmitted data is not compressed.

The following diagram illustrates how the MapR POSIX client (mapr-loopbacknfs) works, in comparison with the Linux OS NFS client (left).

The instructions on this page are for the MapR POSIX client. For instructions on setting up NFS on a MapR cluster, see Managing MapR NFS.

The table below summarizes the differences in the MapR POSIX client deployment behavior when installed with a MapR cluster where security is disabled or enabled:
Cluster Security Disabled Cluster Security Enabled
Client Node
  • MapR cluster looks exactly like network attached storage (NAS)
  • POSIX permissions are enforced
  • Single-user authentication
  • Write access is supported only for applications with uid matching authenticated user
Cluster Node
  • MapR cluster looks exactly like NAS
  • POSIX permissions are enforced
  • Secure cluster access is key
  • Best Practice: Use ticket from mapr user