Local Mirroring

A local mirror volume is a mirror volume whose source is on the same cluster. Local mirror volumes are useful for load balancing or for providing a read-only copy of a data set.

You can locate your local mirror volumes in specific servers or on racks with particularly high bandwidth, mounted in a public directory separate from the source volume.

The most frequently accessed volumes in a cluster are likely to be the root volume and its immediate children. In order to load-balance read operations on these volumes, mirror the root volume (typically mapr.cluster.root, which is mounted at /). By mirroring these volumes, read requests can be served from the mirrors, distributing load across the nodes. Less-frequently accessed volumes that are lower in the hierarchy do not need mirror volumes. Since the mount paths for those volumes are not mirrored throughout, those volumes are writable.

The following sections provide information about how to create local mirror volumes: