Your Browser is Out of Date

Nytro.ai uses technology that works best in other browsers.
For a full experience use one of the browsers below
Dell Unity: Data Reduction
Executive summary Dell Unity Data Reduction Licensing Overview Theory of Operation Management Interoperability
Interoperability
Data at Rest Encryption
Replication
Snapshots
Thin Clones
Dell Unity Native File and Block Import
Pool Expansion
Conclusion Appendix: Technical support and resources

Pool Expansion

Home > Storage > Unity XT > Storage Admin > Dell Unity: Data Reduction > Pool Expansion

Pool Expansion

  • In UnityOS versions prior to the 5.2 release, expanding a Pool residing on a Hybrid Flash System which contains data reduction savings is only supported if it is being expanded by supported Flash Drives. For instance, a Pool containing SAS Flash 2 or SAS Flash 3 drives can be expanded by adding more SAS Flash 2 or SAS Flash 3 drives to the Pool. While storage resources exist within the Pool which have data reduction enabled or have had data reduction enabled in the past, adding SAS or NL-SAS drives to convert the Pool to a Hybrid Pool is not supported in UnityOS versions prior to the 5.2 release.

    To expand and convert an All Flash Pool to a Hybrid Pool in UnityOS versions prior to the 5.2 release, all storage resources which have data reduction enabled or have used data reduction must be removed from the Pool. For Block resources, Local LUN Move can be used to move the resource’s data to another resource on the same Pool with data reduction disabled, or to another Pool. When utilizing Local LUN Move to relocate a Block device within the same Pool, you must ensure data reduction is disabled on the destination device. For File resources, the data must be migrated to a new resource, either by leveraging Dell Unity Asynchronous Replication or a host based migration tool. Once all resources which have utilized data reduction have been removed from the Pool, the expansion will be allowed. More information about migration options can be found in the Dell Unity: Migration Technologies white paper found on Dell Technologies Info Hub.

    In UnityOS version 5.2 and later, a Pool containing data reduction enabled resources can be expanded as along as the total capacity of the flash tier is at least 10% of the resulting pool capacity. This means adding SAS or NL-SAS drives to convert an All Flash Pool to a Hybrid Pool is supported in UnityOS version 5.2 and later, along with expanding an existing drive tier within the Pool. The pool expansion process is not allowed if the minimum percentage of flash capacity is not met. The minimum Flash requirement is to ensure that Flash capacity is available to store each storage resource’s private space, allowing fast access times during data reduction related updates.