Managing storage device evacuation

An apparatus comprising a computer processor and a computer memory, the computer memory including computer program instructions that, when executed by the computer processor, cause the apparatus to carry out the steps of:

• detecting, by the storage system, an occurrence of a storage device evacuation event associated with a source storage device within a write group, wherein the write group is a subset of storage devices storing a data set and the storage device evacuation event indicates removal of the source storage device;
• responsive to detecting the occurrence of the storage device evacuation event, identifying, by the storage system, a target storage device for receiving data stored on the source storage device;
• migrating, by the storage system, the data stored on the source storage device to the target storage device;
• combining the write group and a second write group into a third write group spanning the set of storage devices;
• and
• rebuilding segments of the third write group to accommodate a number of storage devices in the set of storage devices, including rebuilding, by a garbage collection process, each segment into a wider segment.

A computer program product disposed on a computer readable storage medium, the computer program product including computer program instructions that, when executed by a computer processor, cause the computer processor to carry out the steps of:

• detecting, by the storage system, an occurrence of a storage device evacuation event associated with a source storage device within a write group, wherein the write group is a subset of storage devices storing a data set and the storage device evacuation event indicates removal of the source storage device;
• responsive to detecting the occurrence of the storage device evacuation event, identifying, by the storage system, a target storage device for receiving data stored on the source storage device;
• migrating, by the storage system, the data stored on the source storage device to the target storage device;
• combining the write group and a second write group into a third write group spanning the set of storage devices;
• and
• rebuilding segments of the third write group to accommodate a number of storage devices in the set of storage devices, including rebuilding, by a garbage collection process, each segment into a wider segment.