PowerScale OneFS Web Administration Guide

File pool policies

File pool policies define sets of files—file pools—and where and how they are stored on your cluster. You can configure multiple file pool policies with filtering rules that identify specific file pools and the requested protection and I/O optimization settings for these file pools. Creating custom file pool policies requires an active SmartPools license.

The initial installation of OneFS places all files into a single file pool, which is subject to the default file pool policy. Without an active SmartPools license, you can configure only the default file pool policy, which controls all files and stores them anywhere on the cluster.

With an active SmartPools license, OneFS augments basic storage functions by enabling you to create custom file pool policies that identify, protect, and control multiple file pools. With a custom file pool policy, for example, you can define and store a file pool on a specific node pool or tier for fast access or archival purposes.

When you create a file pool policy, flexible filtering criteria enable you to specify time-based attributes for the dates that files were last accessed, modified, or created. You can also define relative time attributes, such as 30 days before the current date. Other filtering criteria include file type, name, size, and custom attributes. The following examples demonstrate a few ways you can configure file pool policies:

• A file pool policy to set stronger protection on a specific set of important files.
• A file pool policy to store frequently accessed files in a node pool that provides the fastest reads or read/writes.
• A file pool policy to evaluate the last time files were accessed, so that older files are stored in a node pool best suited for regulatory archival purposes.

When the SmartPools job runs, typically once a day, it processes file pool policies in priority order. You can edit, reorder, or remove custom file pool policies at any time. The default file pool policy, however, is always last in priority order. Although you can edit the default file pool policy, you cannot reorder or remove it. When custom file pool policies are in place, the settings in the default file pool policy apply only to files that are not covered by another file pool policy.

When a new file is created, OneFS chooses a storage pool based on the default file pool policy, or, if it exists, a higher-priority custom file pool policy that matches the file. If a new file was originally matched by the default file pool policy, and you later create a custom file pool policy that matches the file, the file will be controlled by the new custom policy. As a result, the file could be placed in a different storage pool the next time the SmartPools job runs.