Starting the mapr-loopbacknfs Service to Access a Cluster

Describes the prerequisites and the process of starting the mapr-loopbacknfs service to access a secure cluster.

The following instructions explain how to start the loopbacknfs service so you can access either a non-secure or secure cluster.

To access multiple clusters, ensure that the first cluster that you configure is a HPE Ezmeral Data Fabric 4.0.2 or later cluster, with available POSIX client licenses.

Prerequisites for accessing a secure cluster:

  • Ensure that the stock Linux NFS service is not running. Linux NFS and HPE Ezmeral Data Fabric NFS cannot run concurrently.
  • Disable the lock manager (nlockmgr).
  • Check that the rpcbind service is running on RHEL and CentOS v6.0 and higher. You can use the command ps ax | grep rpcbind to check.
  • Check that the portmapper service is running on RHEL and CentOS v5.x and lower, and on Ubuntu and SLES. You can use the command ps ax | grep portmap to check.
  • Make sure you have applied a Community Edition (M3) license or an Enterprise Edition (M5) license (paid or trial) to the cluster. See Adding a License.
  • Enable security for the cluster. See Enabling Wire-level Security and Disabling Wire-level Security wire-level security.
NOTE
Securing the cluster so that only one user can have secure access provides tight control over cluster access, but it also means that any user on the client who is able to read the generated ticket has read access to all data in the cluster.

Start the mapr-loopbacknfs service and mount the volume

Complete the following steps from your client node, except where noted, to start the mapr-loopbacknfs service and mount the volume:

  1. Use the scp utility to copy the mapr-clusters.conf file from any cluster node to the /usr/local/mapr-loopbacknfs/conf/ directory on the loopbacknfs client node.
    scp /opt/mapr/conf/mapr-clusters.conf root@<client_ip>:/usr/local/mapr-loopbacknfs/conf/mapr-clusters.conf
  2. Generate a user ticket. See Generating a HPE Ezmeral Data Fabric User Ticket for instructions. If you do not have your HPE Ezmeral Data Fabric user ticket with full control Access Control List (ACL) authorization on the cluster, you must have a cluster administrator do the following for you.
    1. In the HPE Ezmeral Data Fabric cluster, navigate to the cluster node to which you want to connect.
    2. Log on to the cluster node as an administrator by running the maprlogin passwordcommand.
    3. Run the maprlogin generateticket -type service -user <user> -duration 365:0:0 -out /tmp/nfsticket command to generate the user ticket.
    If the service ticket expires, the POSIX client:
    • Automatically uses the renewed service ticket without requiring a restart, if the ticket is replaced before expiration (that is, ticket expiry time + grace period of 55 minutes). If the ticket is replaced after expiration, the POSIX loopbacknfs client does not refresh the ticket as the mount becomes stale.
    • Allows impersonation if a service ticket is replaced before ticket expiration (that is, ticket expiry time + grace period of 55 minutes) with a servicewithimpersonation ticket.
    • Honors all changes in the user IDs/group IDs of the renewed ticket.
  3. Copy the user ticket file /tmp/nfsticket from the cluster node where you generated it to the /usr/local/mapr-loopbacknfs/conf directory on the client node running the HPE Ezmeral Data Fabric POSIX client.
    NOTE
    Since the NFS server runs based on a single user's ticket, it can act on behalf of only one user. Therefore, the UID or GID associated with the ticket must match the UID or GID of any user who accesses the NFS server through the HPE Ezmeral Data Fabric POSIX Client.
  4. Create the /usr/local/mapr-loopbacknfs/conf/env.sh file with the 644 permissions (read permission for all users and write permission for owner) on the file, if the file is not already present. Add the path of the maprticket path file location to env.sh. 
    export MAPR_TICKETFILE_LOCATION=/usr/local/mapr-loopbacknfs/conf/nfsticket
  5. Start the mapr-loopbacknfs service from the command line. 
    service mapr-loopbacknfs start
  6. Create a mount point at /mapr and mount the client node to it.
    mkdir /mapr
mount localhost:/mapr /mapr
  7. Automate the mounting of the volume with every launch of the mapr-loopbacknfs service. On the POSIX client node, create /usr/local/mapr-loopbacknfs/conf/mapr_fstab and add the following line:
    localhost:/mapr /mapr hard,nolock