HPE Ezmeral Data Fabric 6.2 is In Maintenance and transitions to "End of Maintenance" in June 2024. Please see the latest documentation.

About Release 6.2
This site contains documentation for HPE Ezmeral Data Fabric release 6.2 including installation, configuration, administration, and reference content, as well as content for the associated bundled ecosystem components and drivers.
6.2 Installation
This section contains information about installing and upgrading HPE Ezmeral Data Fabric software. It also contains information about how to migrate data and applications from an Apache Hadoop cluster to a HPE Ezmeral Data Fabric cluster.
6.2 Data Fabric
HPE Ezmeral Data Fabric is the industry-leading data platform for AI and analytics that solves enterprise business needs.
6.2 Administration
This section describes how to manage the nodes and services that make up a cluster.
- Administering Users and Clusters
  Lists topics that help manage a data-fabric cluster.
- Administering Nodes
  Provides a synopsis of managing nodes in a cluster.
- Administering Volumes
  This section provide information about how to organize and manage data using volumes, a unique feature of HPE Ezmeral Data Fabric clusters.
- Administering Files and Directories
- Administering Tables
  Administration of the HPE Ezmeral Data Fabric Database is done primarily via the command line (maprcli) or with the Managed Control System (MCS). Regardless of whether the HPE Ezmeral Data Fabric Database table is used for binary files or JSON documents, the same types of commands are used with slightly different parameter options. HPE Ezmeral Data Fabric Database administration is associated with tables, columns and column families, and table regions.
- Administering Streams
- Administering Data Fabric Gateways
  A HPE Ezmeral Data Fabric gateway mediates one-way communication between a source HPE Ezmeral Data Fabric cluster and a destination cluster. You can replicate HPE Ezmeral Data Fabric Database tables (binary and JSON) and HPE Ezmeral Data Fabric Streams streams. HPE Ezmeral Data Fabric gateways also apply updates from JSON tables to their secondary indexes and propagate Change Data Capture (CDC) logs.
- Administering Services
- Monitoring the Cluster
  This section describes how to monitor the health and performance of a MapR cluster.
- Configuring Security
  Describes how to configure security and manage secure clusters.
- Managing Secure Clusters
  Provides procedures that will enable you to use MapR clusters securely.
- Administering the Data Access Gateway
  The HPE Ezmeral Data Fabric Data Access Gateway is a service that acts as a proxy and gateway for translating requests between lightweight client applications and the HPE Ezmeral Data Fabric cluster. This section describes considerations when upgrading the service, how to modify configuration settings, and how to administer and manage the service.
- Planning for High Availability
- Administrator's Reference
  This section contains in-depth reference information for the administrator.
  - maprcli and REST API Syntax
    This section provides information about the HPE Ezmeral Data Fabric command API. Most commands can be run on the command-line interface (CLI), or by making REST requests programmatically or in a browser.
    - Overview
      Each command reference page includes the command syntax, a table that describes the parameters, and examples of command usage.
    - acerole validate
      Verifies given user roles for ACEs exists in the /opt/mapr/conf/m7_permissions_roles_refimpl.conf file.
    - acl
      Describes the acl commands used to access control lists (ACLs).
    - alarm
      Describes the alarm commands that perform functions related to system alarms.
    - audit
      Describes commands used to audit operations related to cluster management and data access.
    - blacklist
      Describes commands used to blacklist and to list blacklisted users.
    - cluster
      Manages cluster features, gateways, and cluster-wide settings.
    - config
      Lists configuration values for the data-fabric cluster.
    - dashboard info
      Displays a summary of information about the cluster.
    - dialhome
    - disk
      Lists disk parameters.
    - dump
      Returns key information about volumes, containers, storage pools, and MapR cluster services for debugging and troubleshooting.
    - entity
      Manages entities (users and groups).
    - fid
      Displays information about HPE Ezmeral Data Fabric Database or file-system components that are identified by a FID.
    - file
      Lets you perform tiering operations at the file level.
    - filefilter
      Creates and modifies filters to restrict certain file types from being stored on specified volumes.
    - job
      Manages Hadoop jobs running on the cluster.
    - license
      Manages MapR licenses.
    - label
      Manages registration and modification of labels.
    - nfsmgmt
      Refreshes NFS exports and server cache.
    - nfs4mgmt
      Manages NFSv4 server.
    - node
      Manages nodes in the cluster
    - rlimit
      Manages resource usage limits for the cluster.
    - schedule
      Manages schedules.
    - security
    - service list
      Lists all services on the specified node, the memory allocated for each service, the state of each service, and log path for each service.
    - setloglevel
      Sets log level on individual services.
    - stream
      Manages stream functionality.
    - table
      Performs functions related to HPE Ezmeral Data Fabric Database tables.
    - tier
      Lets you create, modify, remove, and retrieve list of tiers and tiering rules.
    - trace
      Lets you view and modify the trace buffer, and the trace levels for the system modules.
    - urls
      Displays the status page URL for the specified service.
    - virtualip
      Manages virtual IP addresses for NFS nodes.
    - volume
      Manages volumes, snapshots and mirrors.
      - volume audit
        Enables or disables auditing on the specified volume.
      - volume balancecontainers
        Balances the containers, or stops the balancing of containers associated with the volume.
      - volume balancinginfo
        Fetch currently running or scheduled balancer information for one or more volumes.
      - volume compact
        Runs the compactor to remove recalled data on the MapR cluster or stale data on the tier.
      - volume container move
        Moves a container. Permissions required: fc or m on the volume.
      - volume container switchmaster
        Switches the master replica for a specified container to another replica in the replica chain.
      - volume create
        Creates a volume.
      - volume dump create
        Creates a volume dump file containing data from a volume for distribution or restoration.
      - volume dump restore
        Restores or updates a volume from a dump file. Permissions required: fc or restore on the volume.
      - volume fixmountpath
        Corrects the mount path of a volume. Permissions required: fc or m on the volume.
      - volume info
        Displays information about the specified volume. For JSON formatted output, use the -json option when running the command.
      - volume link create
        Creates a link to a volume. Permissions required: fc or m on the volume.
      - volume link remove
        Removes the specified symbolic link. Permissions required: fc or m on the volume.
      - volume list
        Lists information about volumes specified by name, path, or filter.
      - volume mirror push
        Pushes the changes in a volume to all of its mirror volumes in the same cluster, and waits for each mirroring operation to complete.
      - volume mirror start
        Starts mirroring on the specified volume from its source volume.
      - volume mirror status
        Displays the status of the mirroring operation in progress. Use this command to examine the progress of mirroring.
      - volume mirror stop
        Stops mirroring on the specified volume.
      - volume modify
        Modifies an existing volume. Permissions required: m or fc on the volume.
      - volume mount
        Mounts one or more specified volumes. Permissions required: fc or m on the volume.
      - volume move
        Moves the specified volume or mirror to a different topology. Permissions required: m or fc on the volume.
      - volume offload
        Offloads data in the volume to the tier.
      - volume recall
        Recalls the offloaded data for the specified volume.
      - volume remove
        Removes the specified volume or mirror. Permissions required: d or fc on the volume.
      - volume rename
        Renames the specified volume or mirror. Permissions required: fc or d on the volume.
      - volume showmounts
        Returns a list of mount points for the specified volume.
      - volume snapshot create
        Creates a snapshot of the specified volume, using the specified snapshot name.
      - volume snapshot list
        Displays info about a set of snapshots.
      - volume snapshot preserve
        Preserves one or more snapshots from expiration.
      - volume snapshot remove
        Removes one or more snapshots.
      - volume tierjobabort
        Terminates an ongoing offload or recall operation for a volume (specified by name).
      - volume tierjobstatus
        Retrieves the status of the currently running operation (such as offload, recall, or terminate) for a volume.
      - volume tierstats
        Retrieves statistics on the offload and recall operation.
      - volume unmount
        Unmounts one or more mounted volumes. Permissions required: fc or m on the volume.
      - volume upgradeformat
        Upgrades and old-type volume to a new-type volume, which can in turn be used as a promotable mirror volume. Permissions required: m or fc on the volume.
      - volume snapshot restore
        Restores a volume from a snapshot using the CLI.
      - volume snapshot restorestatus
        Displays the progress of the snapshot restore operation, in terms of percentage.
  - Utilities
    Contains information about various scripts and utilities, that help setup, maintain, and monitor clusters.
  - Configuration Files
    This section contains reference information about various configuration files.
  - Alarms Reference
    The pages in this section provide details about all of the types of alarms.
  - HPE Ezmeral Data Fabric Environment
    This section provides information associated with the Data Fabric environment.
- Troubleshooting Cluster Administration
  Lists the common errors and their solutions.
- Best Practices for Backing Up HPE Ezmeral Data Fabric Information
  Lists the best practices and performance considerations to follow when backing up HPE Ezmeral Data Fabric information.
6.2 Development
This section contains information related to application development for Ezmeral ecosystem components and HPE Ezmeral Data Fabric products, including the file system, Database (Key-Value and JSON), and Event Streams.
Other Docs
This section contains release-independent information, including: Installer documentation, Ecosystem release notes, interoperability matrices, security vulnerabilities, and links to other data-fabric version documentation.
Glossary
Definitions for commonly used terms in MapR Converged Data Platform environments.

volume mirror start

Starts mirroring on the specified volume from its source volume.

License required: Enterprise Edition
Permissions required: fc or restore on the volume

When a mirror is started, the mirror volume is synchronized from a hidden internal snapshot so that the mirroring process is not affected by any concurrent changes to the source volume. The volume mirror start command does not wait for mirror completion, but returns immediately. The changes to the mirror volume occur atomically at the end of the mirroring process; deltas transmitted from the source volume do not appear until mirroring is complete.

To provide rollback capability for the mirror volume, the mirroring process creates a snapshot of the mirror volume before starting the mirror, with the following naming format: <volume>.mirrorsnap.<date>.<time>.

Normally, the mirroring operation transfers only deltas from the last successful mirror. Under certain conditions (mirroring a volume repaired by fsck, for example), the source and mirror volumes can become out of sync. In such cases, it is impossible to transfer deltas, because the state is not the same for both volumes. Use the -full option to force the mirroring operation to transfer all data to bring the volumes back in sync.

Syntax

CLI

maprcli volume mirror start
    [ -cluster <cluster> ]
    [ -full true|false ]
    -name <volume name>

REST

Request Type	POST
Request URL	`http[s]://<host>:<port>/rest/volume/mirror/start?<parameters>`

Parameters

Parameter	Description
`cluster`	The cluster on which to run the command.
`full`	Specifies whether to perform a full copy of all data. If false, only the deltas are copied.
`name`	The volume for which to start the mirror.

Output

Sample Output

messages                                            
Started mirror operation for volumes 'testMirror'

Examples

Start mirroring the mirror volume "testMirror":

maprcli volume mirror start -name testMirror

https://abc.sj.us:8443/rest/volume/mirror/start?name=testMirror