Perle Systems Technical Notes
Many companies in the past have managed remote console ports through standard terminal servers. However their use with Solaris servers poses a unique challenge.
If a Solaris system is powered up without a monitor or keyboard connected, the serial port is automatically configured as a console management port. The entire Solaris system can be managed from this port.
When the need arises the administrator has the ability to shut the system down to the “Open Boot Prompt” (OBP). The shut down takes the systems down to an engineering level and shuts all other services down. This happens when a ‘break’ signal is sent to the port, which the Solaris system reads as the command to shut down.
Most serial systems such as Terminal Servers send a ‘break’ signal when they are powered on and off. This does not pose a problem in an environment where the Terminal Server is deployed to function only as a terminal server. However, it is fatal when connected to a Solaris system as a management connectivity solution.
When a Terminal Server is powered off it sends a ‘break’ signal from all ports. This signal will automatically shut down all attached Solaris servers. The result is disastrous to any service provider whose mission critical applications are running on those servers.
Some vendors have taken a few novel approaches to the problem. One large router vendor suggests when using their serial port routers as a console/terminal server that a specific Solaris patch be made or that you purchase 3rd party "non-aborting console adapters" at $89 per port or that you solder a resistor across two of the serial pins. All are very cumbersome and time consuming approaches.
By using an IOLAN Console Servers connected to the console ports on the Solaris servers, “break” signals are prevented from being sent to the Solaris server should the console server be powered off. This eliminates accidental downtime which would occur without this feature.
Administrators can also send an intentional “break” across the network to the Solaris server through the use of a special key sequence understood by the IOLAN.
Perle IOLAN Terminal Servers and Console Servers are ideal for managing remote Solaris consoles having the following features;