Re: stubdom questions

[Samuel Thibault <samuel.thibault@eu.citrix.com>]

Hello,

Zhai, Edwin, le Tue 19 Feb 2008 19:39:41 +0800, a écrit :
> I have a try with HVM stubdomain on r17062, but failed to make on 32b platform.
> Attached patch can fix it, but don't know if okay.

That is how such issues have usually been solved so I guess in principle
it is.  Is your code coming from freebsd too?

> After installation, I failed to start stubdom. So I created it manually

See the commented "xm create" line in the stubdom-dm script, to enable
debugging.

> 1. I use default vnclisten. Does it matter?

Yes:

> #----------------------------------------------------------------------------
> # address that should be listened on for the VNC server if vnc is set.
> # default is to use 'vnc-listen' setting from /etc/xen/xend-config.sxp
> #vnclisten="localhost"

So if your vnc-listen setting is e.g. localhost, the VNC server of the
stubdom will be restricted to the stub domain itself, and you won't be
able to connect.


> 2. Seems qemu in stubdom has some issue and couldn't update the 'vnc-port' in 
> xenstore.

Actually mini-os has no name resolving support so that it won't be able
to understand the default "localhost" for vnclisten and hence not start
VNC.

> Or the stubdom didn't run at all.

It did: messages like

******************* BLKFRONT for /local/domain/45/device/vbd/5632 **********

come from Mini-OS and mean that qemu is currently connecting to the
block backend.

> 3. "Create /etc/xen/stubdom-hvmconfig" in readme -- seems "hvmconfig" should 
> match the domain name rather than config file.

Oh indeed, here is a patch to fix that and other documentation/debugging
issues:


- Document that for vnclisten names and 127.0.0.1 should not be used.
- Documentation cosmetic fixes
- Dump qemu output to the usual logs

Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>

diff -r e85399173769 stubdom/README
--- a/stubdom/README	Tue Feb 12 16:59:08 2008 +0000
+++ b/stubdom/README	Mon Feb 25 11:51:48 2008 +0000
@@ -16,10 +16,12 @@
 
 In your HVM config "hvmconfig",
 
-- use VNC, set vnclisten to "172.30.206.1" for instance:
+- use VNC, set vnclisten to "172.30.206.1" for instance.  Do not use a host name
+as Mini-OS does not have a name resolver.  Do not use 127.0.0.1 since then you
+will not be able to connect to it.
 
-vnc=1 
-vnclisten="172.30.206.1" 
+vnc = 1
+vnclisten = "172.30.206.1"
 
 - use /usr/lib/xen/bin/stubdom-dm as dm script
 
@@ -28,14 +30,15 @@
 - comment the disk statement:
 #disk = [  'file:/tmp/install.iso,hdc:cdrom,r', 'phy:/dev/sda6,hda,w', 'file:/tmp/test,hdb,r' ]
 
-Create /etc/xen/stubdom-hvmconfig ("hvmconfig" must match your main config file)
-with
+Create /etc/xen/stubdom-hvmconfig (where "hvmconfig" is your HVM guest domain
+name) with
 
-kernel="/usr/lib/xen/boot/stubdom.gz"
-vif=[ 'ip=172.30.206.1', 'ip=10.0.1.1,mac=aa:00:00:12:23:34']
+kernel = "/usr/lib/xen/boot/stubdom.gz"
+vif = [ 'ip=172.30.206.1', 'ip=10.0.1.1,mac=aa:00:00:12:23:34']
 disk = [  'file:/tmp/install.iso,hdc:cdrom,r', 'phy:/dev/sda6,hda,w', 'file:/tmp/test,hdb,r' ]
 
 where
 - 172.30.206.1 is the IP for vnc,
-- 'ip=10.0.1.1,mac=' is the same net configuration as in the hvmconfig script,
+- 'ip=10.0.1.1,mac= etc...' is the same net configuration as in the hvmconfig
+script,
 - and disk = is the same block configuration as in the hvmconfig script.
--- a/stubdom/stubdom-dm	Tue Feb 12 16:59:08 2008 +0000
+++ b/stubdom/stubdom-dm	Mon Feb 25 11:51:48 2008 +0000
@@ -62,11 +62,12 @@
 
 creation="xm create -c stubdom-$domname target=$domid memory=32"
 
-(while true ; do sleep 60 ; done) | $creation &
+(while true ; do sleep 60 ; done) | $creation > /var/log/xen/qemu-dm-$domid.log &
 #xterm -geometry +0+0 -e /bin/sh -c "$creation ; echo ; echo press ENTER to shut down ; read" &
 consolepid=$!
 
 
+# Wait for vnc server to appear
 while ! vnc_port=`xenstore-read /local/domain/$domid/console/vnc-port`
 do
         # Check that the stubdom job is still alive