Description

This article explains what the Turbo TX process is and why the syslog message "FATAL ERROR: Invalid DB. Exiting Turbotx process" may be seen on MX and PTX platforms and the recommended course of action.

Note: This issue is limited to MPC 7E/8E/9E linecards on MX platforms and FPC-2T and FPC-3T on PTX platforms.

Symptoms

  • FPC is stuck in offline / online cycles.

  • Microkernel core file is seen for the FPC.

Solution

One easy way to check if Turbotx is enabled for the Flexible PIC Concentrator (FPC) is to log in to run the PFE shell command show heap . This command helps in identifying the memory used by different processes running for the FPC.

Sample Output

user@device> request pfe execute command "show heap 0" target fpc0
ID        Base      Total(b)       Free(b)       Used(b)   %   Name
--  ----------   -----------   -----------   -----------  ---   -----------
0    374db000    3221221352    2192159680    1029061672   31  Kernel
1    18000000     402653184     123818440     278834744   69  DMA
2    18d8b000      21221376      21218952          2424    0  Turbotx    <<<<<<<

Turbo TX is a separate process that runs in parallel to the microkernel to handle traffic between the Routing Engine (RE) (control plane) and the Packet Forwarding Engine (PFE) (data plane) on the FPCs. This is done to offload the microkernel and enable faster transmits between the RE and the PFE.

These logs are seen when the Turbotx process exits while there is a microkernel core seen for the FPC. You can check the core by using the following command: 

show system core-dump routing-engine both   <<< Checks for core present on both RE0 and RE1, in case system has RE-level redundancy
If there are multiple occasions where the FPC crashes (which also leads to the log message), contact Support for further investigation.