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Displays information about the SAS expander connected to the SAS Controller.
SHOW EXPANDER [exp_id]
exp_id
Displays information about a specific SAS expander.If an expander ID is not specified, the SAS utility displays all available SAS expanders that the SAS Controller finds.
/FULL
Displays additional information about the expanders in the SAS domain.
SAS> SHOW EXPANDER
Expander 1
Physical Port : 0
SAS WWID : 500508B3-00A1396F
Dev Handle : 9
Num PHYs : 13
SAS Level : 1
Exp Flags Device has configurable route table.
Prog Link Rate Max 3.0Gbps Min 1.5Gbps
HW Link Rate Max 3.0Gbps Min 1.5Gbps
PHY Info Table Routing 3.0Gbps speed
Att Dev Info SMP Target LSI Device
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This example shows information about external SAS Expander 1, which is connected to the SAS Controller.
Displays SAS PHY information for all connections in the SAS Controller.
SHOW PHY [phy_id]
phy_id
Display information about a specific SAS PHY ID. (Use the SAS command SHOW DISK to display SAS PHY IDs.)If a PHY ID is not specified, the utility displays all available PHYs on the SAS Controller.
/ERROR
Displays SAS PHY error counters./FULL
Displays additional information about the PHYs.
SAS> SHOW PHY 0
PHY 0
OwnerDev : 1
SAS WWID : 5000C500-003306B1
DevHandle : 9
PhyIdentifier : 0
Device Info SSP Target Direct Attached
Flag SGPIO DA Enclosure present.
PHY Info 3.0Gbps speed
SAS>
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This example shows the SAS PHY connection for PHY 0.
Displays the IR volumes configured in the SAS Controller.
SHOW UNIT [volume_id]
volume_id
Displays information about a specific IR volume.If a volume ID is not specified, the SAS utility displays all available IR volumes that the SAS Controller finds.
/FULL
Displays additional information about IR volumes.
SAS> SHOW UNIT
IR Volume information:
--------------
IR Volume 4
--------------
Volume Type : RAID 1 (LSI Logic Integrated Mirror)
Volume State : Optimal
Size : 69495 MB / 142325760 blocks
IR Disk 1 Source Disk
Disk State : Online
Slot ID : 1
SAS WWID : 5000C500-0134CB8D
IR Disk 0 Secondary Disk
Disk State : Online
Slot ID : 7
SAS WWID : 5000C500-0134DBB5
IR Hot Spare 7
Hot Spare Status : Active
Slot ID : 6
SAS WWID : 12210000-06000000
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This example displays volume information and all physical disks corresponding to the IR volume set.
Displays the version number of the SAS utility that you are currently using.
SHOW VERSION
SAS> SHOW VERSION
SAS$UTIL Version 1.0
Build 05-May-2006
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This example shows that this version of the SAS utility is 1.0.
The SCA Control Program (SCACP) utility is designed to monitor and manage cluster communications. It is derived from the Systems Communications Architecture (SCA), which defines the communications mechanisms that allow nodes in an OpenVMS Cluster system to cooperate.
SCA does the following:
Historically, LAN cluster port information has been available only in the System Dump Analyzer (SDA) utility and by using the Availability Manager management tool. The ability to start and stop PEdriver on a LAN device was provided by SYS$EXAMPLES:SYS$LAVC_START_BUS.EXE and SYS$LAVC_STOP_BUS.EXE. No way existed to prioritize use of LAN devices or individual channels.
SCACP provides an alternative method of collecting cluster management data and exercising management control over cluster communications. OpenVMS Version 7.3 introduced SCACP's ability to manage SCA use of LAN paths. Beginning with OpenVMS Version 7.3-1, you can use SCACP to manage all OpenVMS Cluster interconnects.
Starting with OpenVMS Version 8.4, OpenVMS is enhanced to use IP
(Internet Protocol) for cluster communications. OpenVMS cluster over IP
(also referred to as IP Cluster Interconnect) is the ability to use
TCP/IP stack for cluster communications in addition to LAN. PEdriver
which implements the cluster communication protocol uses UDP (User
datagram protocol) for cluster communication.
21.1.1 Terminology Related to SCACP
Definitions of terms that are related to SCACP are in the following
sections.
21.1.1.1 SCS Ports and Circuits
SCA communications mechanisms between nodes are defined in terms of System Communications Services (SCS) ports and circuits:
After a circuit is formed between two ports, communication using the SCS services can be established between SYSAPs in the nodes. In a cluster, each port maintains a circuit with every other remote port.
Circuits provide the SCS layer with the following standardized SCS services:
A virtual circuit (VC) is the interconnect-specific transport layer connection within a circuit that provides reliable port-to-port communication. In other words, VCs are the details of a circuit concerned with interconnect-specific reliable data delivery.
Circuits ensure the following:
The concepts of circuits and virtual circuits are so closely related that usually it has been unnecessary to differentiate between them because SHOW CLUSTER provides no view of the internal operation of a circuit. SCACP, however, makes the differentiation necessary by providing this internal view.
If cluster over IP is enabled, the virtual circuit can consist of both LAN and IP channels for cluster communications. Beginning with OpenVMS Version 7.3, SCACP has been used to manage and display information about the VCs underlying the circuits between LAN ports. Because SCACP displays different types of information about circuits and VCs, its commands must differentiate between them.
LAN cluster communications create virtual circuits using the NI-SCA Transport Protocol to communicate over LAN hardware, providing datagram services.
Cluster over IP create virtual circuits using the NI-SCA Transport
Protocol to communicate over IP network using UDP protocol.
21.1.1.3 LAN Channels
A channel is a logical communication path between two LAN devices. Each channel between two nodes is determined by a local-remote pair of devices and the connecting network. For example, two nodes, each having two LAN devices, can establish up to four channels. The messages that a particular virtual circuit carries can be sent over any of the channels connecting the two nodes.
The LAN cluster driver, PEdriver, builds reliable virtual circuits
using channels that the LAN adapters (devices) and the network
connections define. It then uses these VCs to provide circuits to SCS.
21.1.1.4 IP Channels
Starting from OpenVMS Version 8.4, with the OpenVMS cluster over IP support, a channel is also a logical path between two IP interfaces. Each channel between two nodes is determined by a local-remote pair of devices and the connecting network. For example, two nodes, each having two LAN devices, can establish up to four channels. Similarly two nodes each having two IP interfaces (for example, IE0 and IE1 in Node A and WE0 and WE1 in node B) can establish up to four channels (IE0-WE0, IE0-WE1, IE1-WE0, IE1-WE1). The messages that a particular virtual circuit carries can be sent over any of the channels connecting the two nodes.
The IP cluster driver, PEdriver, builds reliable virtual circuits using
channels that the IP interfaces and the network connections define. It
then uses these VCs to provide circuits to SCS.
21.1.1.5 Channels and Virtual Circuits
The differences between channels and virtual circuits are the following:
Multiple channels can exist between nodes in an OpenVMS Cluster system, but only one LAN/IP -based virtual circuit can exist between any two nodes at a time.
A virtual circuit can have both LAN and IP channels given that the two nodes can communicate using LAN as well as IP. However, by default the PE driver uses LAN channel for optimum performance. |
The following sections explain more recent functionality available for
SCA circuits and ports and more recent support for SCS dynamic load
class.
21.1.2.1 Ability to Set Port and Circuit Priorities
Beginning with OpenVMS Version 7.3-1, you have been able to exercise management control over the circuits chosen to be used for SCS connections. This control allows you to override the automatic selection of the circuit with the highest load class value.
To override automatic circuit selection, assign a management priority value to a specific circuit or SCA port. (A circuit's current priority value is the sum of the local port's management-assigned priority and the management priority value assigned to that circuit.)
Connections are assigned to a circuit with the highest priority. If multiple circuits have the highest priority value, then the circuit with the highest load class is selected.
A change in a circuit's current priority has one of the following effects:
Whenever a circuit is closed, its management priority setting is lost. This is because the data structure containing information about a circuit is deallocated each time a circuit is closed. When a circuit is reopened, the structure is initialized with default values. Thus, circuit management priority does not propagate across VC closures. |
You can use SCACP to enable or disable checksumming on a per-VC basis.
For example, in a disaster-tolerant cluster, you might want to enable
only checksumming on VCs to nodes at the remote site to ensure that
failure of a LAN/IP device's checksumming function resulting in
corrupted packets does not propagate to the remote site.
21.1.2.3 SCS Dynamic Load Class Support
Prior to OpenVMS Version 7.3-1, the load class of SCS circuits was determined only by the port's hard-coded load class value. As a result, CI or DSSI circuits were chosen over a Gigabit Ethernet circuit. Beginning with OpenVMS Version 7.3-1, PEdriver has dynamically updated the load class value of its SCS circuits to reflect the performance of the underlying LAN/IP path or paths currently in use.
If the circuits have the same priority, a change in a circuit's load class has one of the following effects:
Beginning with V7.3-1, SCACP has provided the ability to display information about one cluster interconnect's local ports and their circuits with remote ports.
SCACP port and circuit data is intended to provide the information necessary to exercise management control over ports and circuits. SCACP is not intended to replace the copious data that SHOW CLUSTER provides for ports and circuits. The SHOW CLUSTER and SCACP utilities are intended to be used together to manage cluster communications.
SCACP port and circuit data show the following:
You can also manage cluster communications by assigning a priority
value to individual ports or circuits. See the SET CIRCUIT and SET PORT
command descriptions.
21.1.4 Managing LAN/IP Cluster Ports
To manage LAN/IP cluster ports, you can use common port and circuit commands. Additional commands exist for LAN/IP port VCs, channels, and LAN devices on nodes in the cluster, IP interfaces in nodes in the cluster:
SCACP allows you to set channel and LAN/IP device priority. SCACP also allows you to start and stop PEdriver on LAN devices or IP interfaces.
Using the PEdriver Event-Tracing Facility
The LAN/IP cluster port driver, PEdriver, includes an event-tracing facility that collects a small amount of information for each defined event and saves it in a buffer associated with the virtual circuit or channel. (Any event not associated with a particular virtual circuit or channel is saved in a global PEdriver trace buffer.)
The event trace data is used when debugging, performing dump analysis, and looking at detailed aspects of PEdriver operation.
The TRACE commands are reserved for use by OpenVMS Engineering and HP Services under OpenVMS Engineering direction only. Trace commands and output are subject to change from release to release. |
You can use SCACP to diagnose cluster communications problems. The
appendix "Troubleshooting the NISCA Protocol" in
HP OpenVMS Cluster Systems provides troubleshooting strategies to help cluster or
network managers use SCACP and other tools to pinpoint network-related
cluster communications problems.
21.1.6 Related Documents
For additional information on the topics covered in this chapter, see the following documents:
The SCA Control Program (SCACP) is a cluster management utility that performs certain privileged cluster communications management functions.
RUN SYS$SYSTEM:SCACP
To invoke SCACP, enter the following command at the DCL prompt:
$ RUN SYS$SYSTEM:SCACP |
SCACP displays the following prompt, at which you can enter SCACP commands using the standard rules of DCL syntax:
SCACP> |
To exit SCACP and return to the DCL command level, enter the EXIT command at the SCACP> prompt or press Ctrl/Z.
OpenVMS Version 7.3 and later require SYSPRV privilege to enter SCACP commands. |
SCACP also requires the following privileges:
$ CREATE COUNT.COM
SHOW LAN_DEVICE/COUNTERS
SPAWN WAIT 00:01:00
@COUNT
[Ctrl/Z]
$ RUN SYS$SYSTEM:SCACP
SCACP> @COUNT
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This example creates and runs a command procedure, COUNT.COM, which displays device counters once a minute.
SCACP commands are provided for the following types of functions:
The SCACP commands are shown in Table 21-1.
| Command | Function |
|---|---|
| SCACP Display Commands Qualifiers | |
| SHOW CHANNEL | Displays PEdriver channel information. |
| SHOW CHANNEL/LAN | Displays PEDRIVER LAN channel information. |
| SHOW CHANNEL/IP | Displays PEDRIVER IP channel information. |
| SHOW CIRCUIT (nodename) | Shows information about all virtual circuits between this node and other cluster nodes. |
| SHOW LAN_DEVICE | Displays PEdriver LAN device information. |
| SHOW PORT | Displays information about all SCA ports on the node, including the LAN port, PEA0. |
| SHOW VC | Displays PEdriver virtual circuit information. |
| SCACP Operation Commands | |
| SET CHANNEL | Allows a user to set PEdriver channel management options. |
| SET CIRCUIT | Allows a user to set a management priority value for the selected circuit or circuits. |
| SET PORT | Allows a user to set a management priority value for the selected port or ports. |
| SET VC | Allows a user to set PEdriver virtual circuit options. |
| SCACP LAN Device Operation Commands | |
| SET LAN_DEVICE | Sets PEdriver LAN device management options. |
| START LAN_DEVICE | Starts PEdriver on the specified LAN devices. |
| STOP LAN_DEVICE | Stops PEdriver on the specified LAN devices. |
| SCACP IP Device Operation Commands | |
| SET IP_INTERFACE | Sets IP interface management priority parameter. |
| SHOW IP_INTERFACE | Displays PEdriver device IP Interfaces data. |
| START IP_INTERFACE | Starts PEdriver on the IP interface. |
| STOP IP_INTERFACE | Stops PEdriver on the IP interface. |
| SCACP Trace Commands | |
| These commands are reserved for HP use only. | |
| SET TRACE | Sets PEdriver event tracing options. |
| SHOW TRACE | Displays PEdriver event tracing information. |
| START TRACE | Displays PEdriver event tracing. |
| STOP TRACE | Stops PEdriver event tracing. |
| SCACP Miscellaneous Commands | |
| CALCULATE | Calculates values you can use with SET commands to control OpenVMS cluster communications. |
| HELP | Displays help data. |
| RELOAD | This results in PEdriver refreshing the IP unicast address in PE$IP_CONFIG.DAT file and transmits hello packet based on the list. This is used in IP clusters when a node is added to a cluster and IP unicast is used for cluster communication. All the existing members must have the IP address of new nodes for the node to join the cluster. This rule is applicable only if the new node has only IP channels for cluster communication. |
| SPAWN [command] | Spawns and executes a DCL command. |
| @filename | Executes command file. |
| EXIT | Exits SCACP. |
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