[kwlug-disc] setting up a new VM under ubuntu server 10.04 LTS

[Robert P. J. Day]

  what is probably a simple question regarding setting up a VM under
ubuntu server LTS 10.04 (beta, of course).  so here goes.

  i'm proofing someone else's explanation of how to create a new VM
under this pre-release of the OS, and i want to verify the absolute
minimum amount of package install and config i need to create a new
VM, start it, and log into it (presuming i can get it on the
VM-related internal network that will have to be created).

  so, i follow the instructions and run "vmbuilder" with the
appropriate args *but* i completely skip the network configuration
part since i want to test what happens if i ignore that part entirely.

  in any event, i get a new VM, and i can start it, and i can see it
with:

  $ virsh -c qemu:///system list

and it's running.  so far, so good.  now, what madness did i descend
into when i refused to do any net configuration?  as it is, the host
(which is running entirely off of wireless to connect to the outside
world) has this partial excerpt for "ifconfig" output:

...
virbr0    Link encap:Ethernet  HWaddr f2:91:68:4a:06:c2
          inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0
          inet6 addr: fe80::9401:a1ff:fef5:db72/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:98 errors:0 dropped:0 overruns:0 frame:0
          TX packets:156 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:11948 (11.9 KB)  TX bytes:20192 (20.1 KB)

vnet0     Link encap:Ethernet  HWaddr f2:91:68:4a:06:c2
          inet6 addr: fe80::f091:68ff:fe4a:6c2/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:98 errors:0 dropped:0 overruns:0 frame:0
          TX packets:20156 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500
          RX bytes:13320 (13.3 KB)  TX bytes:1057259 (1.0 MB)

wlan0     Link encap:Ethernet  HWaddr 70:1a:04:38:b6:e0
          inet addr:192.168.2.121  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::721a:4ff:fe38:b6e0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:105302 errors:0 dropped:0 overruns:0 frame:0
          TX packets:61115 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:152800975 (152.8 MB)  TX bytes:5380489 (5.3 MB)

...

  what i would *like* to do is leave wlan0 running, of course, but
simply add whatever netconfig i need to have net connectivity between
the host and the guest -- i don't want to get into bridged networking
yet.

  as you can see, the "virbr0" interface on the host appears to have
been configured correctly as a node on the internal 192.168.122.X
network.  but to connect to the newly-running guest, that guest also
must (naturally) be on that same network.  i've done nothing to mess
with the host's /etc/network/interfaces file, so what would i need to
do to that file in order to have host wireless continue to run, while
allowing the newly-started guest to pick up an internal IP address so
that i can do host->guest SSH?

  have i explained this sufficiently?  kind of fuzzy at the moment,
not enough sleep.  *yawn*.

rday
--

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Robert P. J. Day                               Waterloo, Ontario, CANADA

            Linux Consulting, Training and Kernel Pedantry.

Web page:                                          http://crashcourse.ca
Twitter:                                       http://twitter.com/rpjday
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