Migration to L3 cache

L3 cache is enabled by default on new nodes. If you are upgrading your cluster from OneFS 7.1.0 or earlier, you must enable L3 cache manually on node pools that contain SSDs. When you enable L3 cache, OneFS migrates data that is stored on the SSDs to HDD storage disks and then begins using the SSDs as cache.

You can enable L3 cache as the default for all new node pools or manually for a specific node pool, either through the command line or from the web administration interface. L3 cache can be enabled only on node pools with nodes that contain SSDs.

When you enable L3 cache, OneFS displays the following message:

WARNING: Changes to L3 cache configuration can have a long completion time. If this is a concern, please contact Isilon Technical Support for more information.

You must confirm whether OneFS should proceed with the migration. After you confirm the migration, OneFS handles the migration as a background process, and, depending on the amount of data stored on your SSDs, the process of migrating data from the SSDs to the HDDs might take a long time.

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You can continue to administer your cluster while the data is being migrated.