Local Mirroring

Describes the use of local mirror volumes. The local mirror volume and its source are present on the same cluster,

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. To load-balance read operations on these volumes, mirror the root volume (typically mapr.cluster.root, which is mounted at /). By mirroring these volumes, you can serve read requests from the mirrors, and distribute 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.