A storage controller identifies a storage division comprising unreadable data. In response, the storage controller relocates readable data (if any) from the identified storage division. The storage controller may be further configured to associate the unreadable data with a logical address, and to record persistent metadata to indicate that the logical address is mapped to unreadable, corrupt data. The storage controller may clear the corruption indicator from the logical address. The logical address may be cleared in response to determining that the unreadable data is invalid and/or available from another source.