Dell Force10 S25-01-GE-24V FTOS 8.4.2.7 Configuration Guide for E-Series TeraS - Page 399

Note: The show patch command can be used on both the primary and secondary RPMs, as shown here: FTOS(standby)#show patch Patch version Module E.1.1.bgp.1.0 bgp E.2.1.l2mgr.1.0 l2mgr FTOS(standby)# Cpu Timestamp RP1 Mon Jun 22 06:51:23 PDT 2009 RP2 Mon Jun 22 07:11:15 PDT 2009 Process Restartability c e s Process Restartability is supported on platforms: Process Restartability is an extension to the FTOS High Availability system component that enables application processes and system protocol tasks to be restarted. This extension increases system reliability and uptime by first attempting to restart the crashed process on the primary RPM and then executing the failover procedure only as a last resort. Currently, if a software exception occurs, FTOS executes a failover procedure: • In a single-RPM system, the system generates a core dump and reboots. Reloads require the system to read and apply the entire startup-configuration file, which might take long if the startup-configuration is large. Restarting a process saves time because only a portion of the configuration related to the crashed process is read and re-applied. • In a dual-RPM system, the system generates a core dump and fails over to the standby RPM. Restarting a process precludes launching the failover process. Recovery is attempted first locally on the primary RPM, which involves less CPU overhead, increasing system availability for other activities. For both a single and dual-RPM system, when Process Restartability is enabled and a software exception occurs, FTOS: executes a core dump, frees system resources, restarts the failed process, and then updates the restart counter. By default, a process can be restarted a maximum of 3 times within 1 hour. If this limit is exceeded, the FTOS reloads the system reloads or fails over to the secondary RPM. The processes that can be restarted are: • Management-related processes-TACACS+, RADIUS, CLI, SSH, Telnet, Console/Aux • TACACS+/RADIUS-FTOS restarts the process and reapplies the TACACS+ portion of the running configuration. You must enable process restart explicitly. • Console/Aux-FTOS restarts the process; you must log in again after the restart. The threshold for failover is 3 restarts per hour; the fourth restart triggers a failover. The restart configuration is internal, and not user-configurable. • Telnet/SSH-Each SSH and Telnet session is an individual process. If a Telnet or SSH software exception occurs, only your session is cleared, and you must log in again; no other sessions are affected. This behavior is an exception among the other restartable processes in that Telnet and SSH are not literally restarted. Because of this, Telnet and SSH are not subject to the default or configured restart limit; that is, the system never reloads due to a software exception in these processes. However, a core dump is generated. High Availability | 399