A first logical partition in a first processing complex of a server cluster is operated at a first level of a software code. Software code in a second logical partition in the same processing complex is changed to a second level. Processing operations are transferred from the first logical partition in the first processing complex to a third logical partition in a second processing complex of the server cluster. In another aspect, the transferring of processing operations includes quiescing the first logical partition to cause a failover of processing operations from the first logical partition in the first processing complex, to the third logical partition in the second processing complex. In yet another aspect, a failback operation is performed and a first portion of the processing operations are transferred from the third logical partition in the second processing complex, to the second logical partition in the first processing complex. In still another aspect, a second portion of the processing operations may be transferred from the third logical partition in the second processing complex, to the second logical partition in the first processing complex of the server cluster. In one example, the transferring of the second portion of processing operations includes quiescing the third logical partition to cause a failover of processing operations from the third logical partition in the second processing complex, to the second logical partition in the first processing complex. Other embodiments are described and claimed.