Description

If the QFX switch is stuck at the "db>" prompt (debug prompt) certain information should be captured prior to recoverying the device to assist in understanding the root cause of the crash.

Symptoms

The QFX switch is stuck at the "db>" prompt after rebooting the device.  What data should I collect to assist in determing the Root Cause?

Solution


Collect the following command outputs from the "db>" mode prompt and copy them to a file:

db> x/s version
db> alltrace
db> ps
db> show allvms
db> show msgbuf
db> show registers
db> show lock
db> show uma
db>show mlock
db> show thread
db> show intr
db> show allpcpu
db> show pageq
After the previous data collection, enter "panic" to dump a kernel core.  When the switch recovers collect the core dump file.  The core dump file can be found by doing a "show system core-dumps" from the CLI prompt after the switch recovers:

db> panic

A Support Case should be opened via the Juniper Technical Assistance Center (JTAC) and all information should be attached to the case for analysis.