Migrating data in a storage array that includes a plurality of storage devices and a plurality of write buffer devices, including: detecting, by the storage array, an occurrence of a write buffer device evacuation event associated with one or more source write buffer devices; responsive to detecting the occurrence of the write buffer device evacuation event, determining, by the storage array, whether the storage array includes at least a predetermined amount of write buffer resources in addition to the one or more source write buffer devices; and responsive to determining that the storage array includes at least a predetermined amount of write buffer resources in addition to the one or more source write buffer devices, reducing, by the storage array, write access to the one or more source write buffer devices.