Re: Erratic errors

[David Scott <scott.dj@xxxxxxxxx>]

On Fri, Aug 16, 2013 at 12:05 PM, Anil Madhavapeddy <anil@xxxxxxxxxx> wrote:

On 16 Aug 2013, at 06:31, Vincent Bernardoff <vb@xxxxxxxxxxxxxx> wrote:

> [vb@haramix ~/code/ocaml-vchan/test]% sudo mirari run --xen                                                           [mirari] Using scanned config file node.conf [mirari] + xen mode Parsing config from node.xl Daemon running with PID 6727 libxl: error: libxl_dom.c:35:libxl__domain_type: unable to get domain type for domid=4 Unable to attach console libxl: error: libxl_exec.c:118:libxl_report_child_exitstatus: console child [0] exited with error status 1
>
> [vb@haramix ~/code/ocaml-vchan/test]% sudo mirari run --xen                                                           [mirari] Using scanned config file node.conf [mirari] + xen mode Parsing config from node.xl Daemon running with PID 6737 libxl: error: libxl_dom.c:35:libxl__domain_type: unable to get domain type for domid=5 Unable to attach console libxl: error: libxl_exec.c:118:libxl_report_child_exitstatus: console child [0] exited with error status 1
>

This indicates a very early crash and is somewhat irritating -- it would be nice if the console consumer were connected by the toolstack synchronously with domain setup, so that everything is logged.

Yeah, this is annoying. It's probably a deficiency in xenconsoled. FWIW xen 4.2 and later support console stub domains and so we could very^Wrelatively easily write our own console logger which wouldn't have this problem. I'm considering prototyping a domain which is a console consumer and which can either forward the raw stream to a connected real terminal (typically in dom0), or emulate a terminal and expose VNC (like XenServer's "vncterm").

We could put in a hack to the domain exit function in Mirage to check if it's exiting very soon after it's been started, and to spin for a while if that's the case.  Not very pretty though..

A good hack for the moment!

Cheers,

Dave