8.7. Creating Striped Replicated Volumes

Important

Striped-Replicated volume is a technology preview feature. Technology Preview features are not fully supported under Red Hat subscription level agreements (SLAs), may not be functionally complete, and are not intended for production use. However, these features provide early access to upcoming product innovations, enabling customers to test functionality and provide feedback during the development process.

Note

The number of bricks should be a multiple of the replicate count and stripe count for a striped replicated volume.
Striped replicated volumes stripes data across replicated bricks in the trusted storage pool. For best results, you should use striped replicated volumes in highly concurrent environments where there is parallel access of very large files and performance is critical. In this release, configuration of this volume type is supported only for Map Reduce workloads.
Illustration of a Striped Replicated Volume

Figure 8.5. Illustration of a Striped Replicated Volume


To create a striped replicated volume
  1. Create a trusted storage pool consisting of the storage servers that will comprise the volume.
  2. Create a striped replicated volume :
    # gluster volume create NEW-VOLNAME [stripe COUNT] [replica COUNT] [transport tcp | rdma | tcp,rdma] NEW-BRICK...
    For example, to create a striped replicated volume across four storage servers:
    # gluster volume create test-volume stripe 2 replica 2 transport tcp server1:/exp1 server2:/exp3 server3:/exp2 server4:/exp4
    Creation of test-volume has been successful
    Please start the volume to access data.
    To create a striped replicated volume across six storage servers:
    # gluster volume create test-volume stripe 3 replica 2 transport tcp server1:/exp1 server2:/exp2 server3:/exp3 server4:/exp4 server5:/exp5 server6:/exp6
    Creation of test-volume has been successful
    Please start the volume to access data.
    The order in which the bricks are specified determines the mirroring of bricks with each other. For example, first n bricks, where n is the replica count. Hence, the first two bricks specified will mirror each other, and the third and fourth bricks will mirror each other.
    If the transport type is not specified, tcp is used as the default. You can also set additional options if required, such as auth.allow or auth.reject. For more information, see Section 10.1, “Tuning Volume Options”

    Note

    Make sure you start your volumes before you try to mount them or else client operations after the mount will hang, see Section 8.10, “Starting Volumes ” for details.