content_image/1003833.jpg
## Modify reserve capacity 

You can modify the amount of flash storage capacity that is reserved for system management tasks. For non-compression-enabled systems, such as FlashSystem AE1 and AE2, this can be used to improve system performance. For compression-enabled systems such as FlashSystem AE3, reserve space can be used to prevent over-allocating the system. 

Out of the usable flash storage capacity that is available, the system sets aside a specific amount of that capacity for system management tasks, which reduces the overall usable capacity that is available for volumes. 

Select Modify Reserve capacity  and click Modify  to allocate a portion of the usable capacity as shown in Figure 7-27. 

<img src='content_image/1003833.jpg'>

The amount of usable capacity that is available for volumes is reduced and cannot be provisioned. 

## Fibre Channel ports 

To view the Fibre Channel (FC) ports of the IBM FlashSystem 900 interface cards, select System Actions → Fibre Channel Ports . The Fibre Channel Ports window opens. 

In our example, eight 16 Gbps FC ports are displayed, each showing the following information in the default view: 

GLYPH<SM590000> Depiction of port location 

GLYPH<SM590000> Port state 

GLYPH<SM590000> Port speed: Auto, 16 Gbps, 8 Gbps, 4 Gbps, or 2 Gbps 

GLYPH<SM590000> Protocol: Fibre Channel Arbitrated Loop (FC-AL) or Fibre Channel-Peer to Peer (FC-P2P) 

GLYPH<SM590000> WWPN/GUID: Worldwide port name (WWPN) and globally unique identifier (GUID) 

Additional information can be displayed by modifying the view: 

GLYPH<SM590000> Type: FC or Ethernet 

