svn commit: r210561 - projects/sv/sys/net

[Ed Maste]

On Wed, Jul 28, 2010 at 03:10:31PM +0000, Attilio Rao wrote:

> Log:
>   Initial import of the netdump files.
>   They still need a lot of polishing and cleanup so they might not be
>   considered definitive at all.

This code is a port to recent FreeBSD of Darrell Anderson's network
crashdump support, which was done in the 4.x days.  I can't find a
current website with the original versions but archive.org has a cache
of course:

http://web.archive.org/web/20041204223729/http://www.cs.duke.edu/~anderson/freebsd/netdump/

Quoting from the old readme:

  Netdump provides FreeBSD kernel crash dumping over the network.
  Netdump is a FreeBSD kernel module client and user-level server.

  A normal kernel crash writes a raw dump of memory to a dedicated
  partition (usually the swap partition) using a low-level disk routine,
  and then copies that raw dump into a file (via savecore) during the
  following boot process.

  Netdump replaces the standard dump routine. During a crash, a netdump
  client broadcasts to locate a netdump server, then sends the dump as
  UDP/IP packets (with retransmission after loss). The netdump server
  creates a dump file suitable for gdb. If netdump fails (for example,
  no netdump server is located), a normal disk dump is performed. 

There is cleanup work to be done still, but we plan to have this in
shape for 9.0.

-Ed