PCAP File Location

Fastpath PCAP files are written to the /records/pcap directory in same card and CPU complex where the session manager owns the subscriber session resides.

/records directory is mapped to the "tmpfs" filesystem that is mapped to RAM. In this state, the files are suffixed with a ".pending" extension. For example:

-rw-rw-r-- 1 root root 268599296 Sep 23 14:04 vpp_S1_B0_eth.pending
Note

The files size at this stage is not the actual file size when it is written to a persistent storage.

Once the fastpath tracing mechanism has written the files, they are converted to ‘.pcap’ files and renamed as given below. Additionally, there is a file that ends with a ".done" extension:

-rw-rw-r--    1 root     root       8689188 Oct 16 22:06 vpp_S0_B0_eth.pcap

After the PCAP files are written by fastpath tracing mechanism, the Co-Proc functionality instantiates and copies the files to a hard disk or a persistent storage.

The aforementioned file location process for Fastpath is also applicable to Slowpath.

The target file location in all cases is: /hd_raid/records/hexdump, except for the case in the hexdump module configuration where use-harddisk is enabled and the directory option under the hexdump file is to a custom value. For example, if the directory option is set to a value "abc" then the target location for the PCAP file will be: /hd_raid/records/hexdump/abc/.

In this feature implementation, a predefined location is set for PCAP files.

  • To make sure that /records/pcap directory is not populated when issues are encountered with the use of use-harddisk and hexdump module configurations.

  • For regular cleanup from /hd_raid/records/hexdump directory.

File Transfer to External Location

Once the files have been copied to the hard disk, they can be copied over to an external server using the command: transfer-mode option under the hexdump command in the hexdump-module configuration.

Apart from transfer-mode , other relevant options under hexdump can be used for external file transfer. Operators can use these commands to avoid excessive storage during fastpath processing.