dump volumeinfo

Returns information about volumes and the associated containers.

A volume is a logical unit that allows you to apply policies to a set of files, directories, and sub-volumes. Using volumes, you can enforce disk usage limits, set replication levels, establish ownership and accountability, and measure the cost generated by different projects or departments. For more information, see Managing Data with Volumes.

Syntax

CLI
maprcli dump volumeinfo
    [-cluster <cluster name>]
    -volumename <volume name>
Note: For best results, use the -json option from the command line.
REST
N/A

Parameters

Parameter

Description

cluster

The cluster on which to run the command. If this parameter is omitted, the command is run on the same cluster where it is issued. In multi-cluster contexts, you can use this parameter to specify a different cluster on which to run the command.

volumename

The name of the volume. To obtain volume names, use the maprcli volume list command.

Output

The maprcli volume info returns information about the volume and the containers associated with that volume. Volume information includes the ID, volume name, and replication factor. For each container on the specified volume, the command returns information about nodes and storage.

# maprcli dump volumeinfo -cluster docs41cluster -volumename mapr.cluster.root -json
{
    "timestamp":1435363982346,
    "timeofday":"2015-06-26 05:13:02.346 GMT-0700",
    "status":"OK",
    "total":2,
    "data":[
        {
            "VolumeName":"mapr.cluster.root",
            "VolumeId":47274128,
            "VolumeTopology":"/data",
            "VolumeUsedSizeMB":0,
            "VolumeReplication":3,
            "VolumeMinReplication":2,
            "NameSpaceReplication":3,
            "NameSpaceMinReplication":2,
            "ReReplicationTimeOutSec":0,
            "MirrorThrottle":true,
            "AccessTime":"Fri Jun 26 09:38:30 PDT 2015",
            "AuditVolume":"0",
            "Audited":"0",
            "CoalesceInterval":60,
            "limitSpread":true,
            "allowGrant":false
        },
        {
            "ContainerId":2049,
            "Epoch":3,
            "Master":"10.10.100.126:5660-10.10.101.126:5660-172.17.42.1:5660--3-VALID",
            "ActiveServers":{
                "IP:Port":"10.10.100.126:5660-10.10.101.126:5660-172.17.42.1:5660--3-VALID"
            },
            "InactiveServers":{
                
            },
            "UnusedServers":{
                
            },
            "OwnedSizeMB":"0 MB",
            "SharedSizeMB":"0 MB",
            "LogicalSizeMB":"0 MB",
            "TotalSizeMB":"0 MB",
            "NumInodesInUse":41,
            "Mtime":"Fri Jun 26 13:27:35 PDT 2015",
            "NameContainer":"true",
            "CreatorContainerId":0,
            "CreatorVolumeUuid":""
        }
    ]
}

Output fields

Field

Description

VolumeName

The name of the volume.

VolumeId

The unique ID number of the volume.

VolumeTopology

The volume topology corresponds to the node topology of the rack or nodes where the volume resides. By default, new volumes are created with a topology of / (root directory). For more information, see Volume Topology.

VolumeUsedSizeMB

The size on disk (in MB) of the volume.

VolumeReplication

The desired replication factor, the number of copies of a volume. The default value is 3. The maximum value is 6.

VolumeMinReplication

The minimum replication factor, the number of copies of a volume (excluding the original) that should be maintained by the MapR cluster for normal operation. When the replication factor falls below this minimum, writes to the volume are disabled. The default value is 2.

MirrorThrottle

Specifies whether mirror throttling is enabled (true) or disabled (false). Throttling is set on the source volume and applies to all its mirrors. This property was introduced in version 4.0.2.
AccessTime A value that can be used to determine which volumes are accessed regularly. This value is updated every 6 hours with the last time that an operation occurred on the volume. The access time is not updated for changes to volume properties, creation of a snapshot, or synchronization between a volume and a mirror. However, the volume access time is updated the first time you upgrade to a MapR version that includes this property. This property was introduced in version 4.0.2.
limitSpread An internal flag for MapR volumes to control the growth of volume in terms of number of containers. When this flag is set, cldb tries to limit the number of new containers created depending on the present size of volume. If volume size (data in volume) is small, cldb tries to reuse space in existing containers to avoid the creation of new containers. This helps reduce the wasting of containers IDs in an environment that has small volumes.

ContainerId

The unique ID number of the container.

Epoch

A sequence number that indicates the most recent copy of the container. The CLDB uses the epoch to ensure that an out-of-date copy cannot become the master for the container.

Master

The physical IP address and port number of the master copy. The master copy is part of the original copy of the volume.

ActiveServers

The physical IP address and port number of each active node on which the container resides.

InactiveServers

The physical IP address and port number of each inactive node on which the container resides.

UnusedServers

The physical IP address and port number of servers from which no "heartbeat" has been received for quite some time.

OwnedSizeMB

The size on disk (in MB) dedicated to the container.

SharedSizeMB

The size on disk (in MB) shared by the container.

LogicalSizeMB

The logical size on disk (in MB) of the container.

TotalSizeMB

The total size on disk (in MB) allocated to the container. Combines the Owned Size and Shared Size.

Mtime

Indicates the time of the last modification to the contents of the container.

NameContainer

Indicates if the container is the name container for the volume. If true, the container is the volume's first container and replication occurs simultaneously from the master to the intermediate and tail containers.

CreatorContainerId The container ID of the read-write container. The container Id is retained in all mirrors of that containers (in all mirrors of volume). The container ID enables the identification of the correct containers to source from when mirror sources are changed in a mirror chain.
CreatorVolumeUuid A randomly generated unique ID that is shared by all mirrors of a volume and all containers of them. It is used to avoid undesirable chaining of containers when mirror sources are changed in a mirror chain.

Example

CLI
maprcli dump volumeinfo -volumename mapr.cluster.root -json