Patent attributes
Techniques for mapping large storage extents (“ubers”) into storage drive groups (“resiliency groups”) in a data storage system. The techniques can include, as the capacity of storage drives included in a first resiliency group is used up, forming a second resiliency group with one or more new storage drives. The disclosed techniques can further include allocating one or more storage drives from the first resiliency group to the second resiliency group to satisfy a requirement of a predetermined RAID storage configuration, and performing a reduced number of data movement operations to assure that data slices of one or more ubers initially assigned to the first resiliency group are allocated to storage drives in the same first or second resiliency group. In this way, data storage systems can be made to support a desired storage drive expansion with a reduced number of new storage drives.
