PowerScale OneFS: New File Attributes Creation

Creating FilePool Policies with size parameters, and not using path-based parameters, the New File Attributes (NFA) may be set to undesired pool. 

By design for performance benefits, OneFS does not inline all new writes based off all FilePool policy parameters. Scheduling of SmartPools or FilePolicy jobs are required to implement all policy parameters, and policy enforcement. 

NFAs are used to enforce which pool all new writes within a directory are placed. NFAs are set on each directory based on the initial run of a SmartPools job after creating or modifying FilePool Policies. 

Size-based policy parameters, placing X-sized files to a specific pool without path-based parameters, set NFAs for the directories to the specified pool. The file system creates a 0-byte pseudo file for the size-based policies to create the NFAs for new writes to inline to the specified pool.

This can then lead to new writes targeting node pools outside of the expected target pools or expected default target pool. This is corrected once SmartPools or FilePolicy job runs to enforce the file pool policies. 

This is expected behavior, and working as designed. Should there be concern of data not residing on the expected pool, there are some options:

• Use path-based parameters within the file pool policies to ensure that new writes are indeed being made to the expected pool
• Create a filepool policy parameter to omit 0-byte files from a pool of concern to prevent the NFA from being created on the specified pool