Users Guide

Mini Core Dumps
Dell Networking OS supports mini core dumps on the application and kernel crashes. The mini core dump applies to Master, Standby, and
Member units.
Application and kernel mini core dumps are always enabled. The mini core dumps contain the stack space and some other minimal
information that you can use to debug a crash. These les are small les and are written into ash until space is exhausted. When the ash
is full, the write process is stopped.
A mini core dump contains critical information in the event of a crash. Mini core dump les are located in ash:/ (root dir). The application
mini core lename format is f10StkUnit<Stack_unit_no>.<Application name>.acore.mini.txt. The kernel mini core lename format is
f10StkUnit<Stack_unit_no>.kcore.mini.txt. The following are sample lenames.
When a member or standby unit crashes, the mini core le gets uploaded to master unit. When the master unit crashes, the mini core le is
uploaded to new master.
The panic string contains key information regarding the crash. Several panic string types exist, and they are displayed in regular English text
to enable easier understanding of the crash cause.
Example of Application Mini Core Dump Listings
Dell#dir flash:/CORE_DUMP_DIR
Directory of flash:/CORE_DUMP_DIR
1 drwx 4096 Jan 07 2015 13:25:04 +00:00 .
2 drwx 4096 Jan 01 1980 00:00:00 +00:00 ..
3 drwx 4096 Jan 07 2015 13:25:04 +00:00 FTP_STK_MEMBER
4 -rwx 512 May 11 2015 20:54:24 +00:00 f10StkUnit.kcore.mini.txt
flash: 2368282624 bytes total (2293637120 bytes free)
Example of a Mini Core Text File
VALID MAGIC
-----------------PANIC STRING -----------------
panic string is :<null>
---------------STACK TRACE START---------------
0035d60c <f10_save_mmu+0x120>:
00274f8c <panic+0x144>:
0024e2b0 <db_fncall+0x134>:
0024dee8 <db_command+0x258>:
0024d9c4 <db_command_loop+0xc4>:
002522b0 <db_trap+0x158>:
0026a8d0 <mi_switch+0x1b0>:
0026a00c <bpendtsleep>:
----------------STACK TRACE END----------------
--------------------FREE MEMORY---------------
uvmexp.free = 0x2312
Enabling TCP Dumps
A TCP dump captures CPU-bound control plane trac to improve troubleshooting and system manageability. When you enable TCP dump,
it captures all the packets on the local CPU, as specied in the CLI.
You can save the trac capture les to ash, FTP, SCP, or TFTP. The les saved on the ash are located in the ash://TCP_DUMP_DIR/
Tcpdump_<time_stamp_dir>/ directory and labeled tcpdump_*.pcap. There can be up to 20 Tcpdump_<time_stamp_dir> directories. The
21st le overwrites the oldest saved le. The maximum le size for a TCP dump capture is 1MB. When a le reaches 1MB, a new le is
created, up to the specied total number of les.
Maximize the number of packets recorded in a le by specifying the snap-length to capture the le headers only.
The tcpdump command has a nite run process. When you enable the tcpdump command, it runs until the capture-duration timer and/or
the packet-count counter threshold is met. If you do not set a threshold, the system uses a default of a 5 minute capture-duration and/or a
single 1k le as the stopping point for the dump.
Debugging and Diagnostics
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