If  1920  events are occurring, you might need to use a performance monitoring and analysis  tool, such as the IBM Spectrum Control, to help identify and resolve the problem. To create a partnership, use the following command, depending on the connection type: To establish a fully functional MM/GM partnership, you must issue this command on both  systems. This step is a prerequisite for creating MM/GM relationships between volumes on  the IBM Spectrum Virtualize systems. When creating the partnership, you must specify the Link Bandwidth and can specify the  Background Copy Rate: The combination of the Link Bandwidth value and the Background Copy Rate percentage is  referred to as the  Background Copy bandwidth . It must be at least 8 Mbps. For example, if the  Link Bandwidth is set to  10000  and the Background Copy Rate is set to  20 , then the resulting  Background Copy bandwidth that is used for background operations is 200 Mbps. The background copy bandwidth determines the rate at which the background copy is  attempted for MM/GM. The background copy bandwidth can affect foreground I/O latency in  one of the following ways: To set the background copy bandwidth optimally, ensure that you consider all three resources:  Primary storage, intercluster link bandwidth, and auxiliary storage. Provision the most  restrictive of these three resources between the background copy bandwidth and the peak  foreground I/O workload.  Perform this provisioning by calculation or by determining experimentally how much  background copy can be allowed before the foreground I/O latency becomes unacceptable.  Then, reduce the background copy to accommodate peaks in workload.  GLYPH<SM590000> If the background copy bandwidth is set too high for the storage at the secondary site,  background copy writes at the secondary site overload the auxiliary storage, and again  delay the synchronous secondary writes of foreground I/Os. GLYPH<SM590000> If the background copy bandwidth is set too high for the storage at the primary site,  background copy read I/Os overload the primary storage and delay foreground I/Os.  GLYPH<SM590000> The following results can occur if the background copy bandwidth is set too high compared  to the MM/GM intercluster link capacity:  – The background copy I/Os can back up on the MM/GM intercluster link. – There is a delay in t he synchronous auxiliary writes of foreground I/Os. – The foreground I/O latency increases as perceived by applications. GLYPH<SM590000> The Background Copy Rate is the maximum percentage of the Link Bandwidth that can be  used for background copy operations. The default value is 50%.  GLYPH<SM590000> The Link Bandwidth, expressed in Mbps (megabits per second), is the amount of  bandwidth that can be used for the FC or IP connection between the systems within the  partnership.  GLYPH<SM590000> Use the  mkippartnership  command to establish a one-way MM/GM partnership between  the local system and a remote system that are linked over an IP connection. GLYPH<SM590000> Use the  mkfcpartnership  command to establish a one-way MM/GM partnership between  the local system and a remote system that are linked over an FC (or FCoE) connection. 11.7.4 System partnership Background copy bandwidth effect on foreground I/O latency 544  Implementing the IBM Storwize V7000 with IBM Spectrum Virtualize V8.2.1