This topics below describe the behavior of the stripe group affinity feature in the StorNext file system, and it discusses some common use cases.
Note: This section does not discuss file systems managed by StorNext Storage Manager. There are additional restrictions on using affinities for these managed file systems.
The following are terms and definitions are used throughout the topics below.
A stripe group is collection of LUNs (typically disks or arrays), across which data is striped. Each stripe group also has a number of associated attributes, including affinity and exclusivity.
An affinity is used to steer the allocation of a file’s data onto a set of stripe groups. Affinities are referenced by their name, which may be up to eight characters long. An affinity may be assigned to a set of stripe groups, representing a named pool of space, and to a file or directory, representing the space from which space should be allocated for that file (or files created within the directory).
A stripe group which has both an affinity and the exclusive attribute can have its space allocated only by files with that affinity. Files without a matching affinity cannot allocate space from an exclusive stripe group.