HP OpenVMS Systems Documentation

HP Availability Manager User's Guide

You can display interconnect-specific virtual circuit summary data by clicking the handle at the beginning of a Virtual Circuit Summary (black) data row. The screen expands to display the interconnect-specific VC summary data shown in Figure 4-6.

Much of the data in this display corresponds to the information displayed by the SCACP command SHOW VC. The SHOW CLUSTER command does not provide a corresponding display. Which data items are displayed depends on the type of interconnect the virtual circuit is using. Currently, this feature is available only for LAN virtual circuits. VC Summary displays for other cluster interconnects such as CI might be available in the future. When other interconnects are supported, the interconnect type will be displayed at the beginning of the line---for example, CI Virtual Circuit Summary---and the associated heading will have interconnect-specific data items.

Note that LAN Virtual Circuit counters are initialized when PEDRIVER detects the existence of a PEDRIVER on a remote system. All of a LAN VC's counters are cumulative from that time.

Some of the data described in Table 4-6 is not displayed in Figure 4-6 because the screen display is wider than the page. You can scroll to the right on your terminal screen to display the remaining fields described in the table.

Figure 4-6 LAN Virtual Circuit Summary Data

Table 4-6 describes the LAN virtual circuit summary data shown in Figure 4-6.

A LAN path or channel is a logical communication path between two LAN devices. Channels between nodes are determined by a local device, a remote device, and the connecting network. For example, two nodes, each having two devices, might establish four channels between the nodes. The packets that a particular LAN virtual circuit carries can be sent over any open channel connecting the two nodes.

The difference between channels and virtual circuits is that channels provide datagram service. Virtual circuits, layered on channels, provide error-free paths between nodes. Multiple channels can exist between nodes in an OpenVMS Cluster system, but only one LAN-based virtual circuit can exist between any two nodes at a time.

LAN channel counters are initialized when PEdriver detects the existence of a LAN device on a remote system. All of a LAN channel counters are cumulative from that time. For more information about channels and virtual circuits, see the HP OpenVMS Cluster Systems manual.

Displaying Data

You can display LAN channel summary data by clicking the handle in front of the data item OPEN, PATH, or CLOSED under "VC State" for LAN virtual circuit summary data (see Figure 4-6), or by right-clicking a data item and choosing the Channel Summary item from the popup menu. The screen expands to display the LAN channel summary data shown in Figure 4-7.

The data items displayed depend on the type of virtual circuit. Currently, this feature is available only for LAN virtual circuits.

Figure 4-7 LAN Channel Summary Data

Some of the data described in Table 4-7 is not displayed in Figure 4-7 because the screen display is wider than the page. You can scroll to the right on your terminal screen to display the remaining fields described in the table.

The following sections describe detailed data that appears on lines that you can open in the Cluster Members Pane shown in Figure 4-1.

4.3.1 LAN Device Data

You can display device data by first right-clicking a node name on the Cluster Members pane shown in Figure 4-1. On Version 7.3 or later nodes on which managed objects are enabled, the Availability Manager displays a menu with the following choices:

• SCA Summary
• LAN Device Summary
• Fix node-name

Click LAN Device Summary... to display the Device Summary Data page shown in Figure 4-8.

Figure 4-8 LAN Device Summary Data

Table 4-8 describes the LAN device summary data displayed in Figure 4-8. This data is also displayed with SCACP command SHOW LAN_DEVICE.

The Network Interconnect for System Communications Architecture (NISCA) is the transport protocol responsible for carrying packets such as disk I/Os and lock packets across Ethernet and FDDI LANs to other nodes in the cluster.

The LAN virtual circuit details (NISCA) pages show detailed information about the LAN Ethernet or FDDI connection between two nodes. The Availability Manager displays one window for each LAN virtual circuit. This page is intended primarily to provide real-time aids for diagnosing LAN-related cluster communications problems. HP OpenVMS Cluster Systems describes the parameters shown on these pages and tells how to diagnose LAN-related cluster problems.

The LAN Virtual Circuit Details pages provide the same information as the SCACP command SHOW VC and as the following OpenVMS System Dump Analyzer (SDA) commands: PE VC and SHOW PORTS/VC=VC_ remote-node-name. In these commands, remote-node-name is the SCS name of another node in the cluster.

SDA defines VC_remote-node-name and performs the first SHOW PORTS action after SDA is started. Thus, the /CH and /VC options are valid only with the second and subsequent SHOW PORT commands.

You can display LAN virtual circuit details data by double-clicking OPEN or CLOSED under "VC State" for LAN Virtual Circuit Summary on the Cluster Summary page (see Figure 4-7). After a brief delay, a LAN VC Transmit Data page (shown in Figure 4-9) is displayed. The tabs at the top of the page indicate additional pages that you can display.

The data items displayed depend on the type of virtual circuit. Currently, this feature is available only for LAN virtual circuits.

4.3.2.1 LAN VC Transmit Data

Transmit data is information about data packet transmission. Figure 4-9 is an example of a LAN VC Transmit Data page.

Figure 4-9 LAN VC Transmit Data Page

Table 4-9 describes the data displayed in Figure 4-9.

Receive data is information about the receipt of data packets. Figure 4-10 is an example of a LAN VC Receive Data page.

Figure 4-10 LAN VC Receive Data Page

Table 4-10 describes the data displayed in Figure 4-10.

LAN VC congestion control data is information about LAN traffic. The values indicate the number of packets that can be sent to the remote node before receiving an acknowledgment and the retransmission timeout.

Figure 4-11 is an example of a LAN VC Congestion Control Data page.

Figure 4-11 LAN VC Congestion Control Data Page

Table 4-11 describes the data displayed in Figure 4-11.