Does the SunPlex system require a terminal concentrator?
All software releases starting with Sun Cluster 3.0 do not require a terminal concentrator to run. Unlike the Sun Cluster 2.2 product, which required a terminal concentrator for failure fencing, later products do not depend on the terminal concentrator.
I see that most SunPlex servers use a terminal concentrator, but the Sun Enterprise E10000 server does not. Why is that?
The terminal concentrator is effectively a serial-to-Ethernet converter for most servers. Its console port is a serial port. The Sun Enterprise E10000 server doesn't have a serial console. The System Service Processor (SSP) is the console, either through an Ethernet or jtag port. For the Sun Enterprise E10000 server, you always use the SSP for consoles.
What are the benefits of using a terminal concentrator?
Using a terminal concentrator provides console-level access to each node from a remote workstation anywhere on the network, including when the node is at the OpenBoot PROM (OBP).
If I use a terminal concentrator not supported by Sun, what do I need to know to qualify the one that I want to use?
The main difference between the terminal concentrator supported by Sun and other console devices is that the Sun terminal concentrator has special firmware that prevents the terminal concentrator from sending a break to the console when it boots. Note that if you have a console device that can send a break, or a signal that might be interpreted as a break to the console, it shuts down the node.
Can I free a locked port on the terminal concentrator supported by Sun without rebooting it?
Yes. Note the port number that needs to be reset and do the following:
telnet tc Enter Annex port name or number: cli annex: su - annex# admin admin : reset port_number admin : quit annex# hangup #
Refer to the Sun Cluster 3.1 System Administration Guide for more information about configuring and administering the terminal concentrator supported by Sun.
What if the terminal concentrator itself fails? Must I have another one standing by?
No. You do not lose any cluster availability if the terminal concentrator fails. You do lose the ability to connect to the node consoles until the concentrator is back in service.
If I do use a terminal concentrator, what about security?
Generally, the terminal concentrator is attached to a small network used by system administrators, not a network that is used for other client access. You can control security by limiting access to that particular network.
How do I use dynamic reconfiguration with a tape or disk drive?
Determine whether the disk or tape drive is part of an active device group. If the drive is not part of an active device group, you can perform the DR remove operation on it.
If the DR remove-board operation would affect an active disk or tape drive, the system rejects the operation and identifies the drives that would be affected by the operation. If the drive is part of an active device group, go to DR Clustering Considerations for Disk and Tape Drives.
Determine whether the drive is a component of the primary node or the secondary node. If the drive is a component of the secondary node, you can perform the DR remove operation on it.
If the drive is a component of the primary node, you must switch the primary and secondary nodes before performing the DR remove operation on the device.
If the current primary node fails while you are performing the DR operation on a secondary node, cluster availability is impacted. The primary node has no place to fail over until a new secondary node is provided.