Re: [gentoo-user] installing Gentoo in a xen VM

[J. Roeleveld]

On Thursday, December 04, 2014 07:11:12 PM lee wrote:
> Tomas Mozes <tomas.mozes@××××.sk> writes:
> > On 2014-12-04 11:08, lee wrote:
> >> Tomas Mozes <tomas.mozes@××××.sk> writes:
> >>> On 2014-12-04 02:14, lee wrote:

<snipped part already answered>

> > name = "gentoobox"
> > kernel = "/xen/_kernel/kernel-3.14.23-gentoo-xen"
> > extra = "root=/dev/xvda1 net.ifnames=0"
> > memory = 2500
> > vcpus = 4
> > vif = [ '' ]
> > disk = [ '/dev/vg_data/gentoo-t1_root,raw,xvda1,rw' ]
>
> 'raw'?  I'll have to look up what that does.
>
> > You can read about PV:
> > http://wiki.xenproject.org/wiki/Paravirtualization_%28PV%29
> >
> >>> If you prefer HVM, then you create a partition and use the install-cd
> >>> to boot. After your install cd boots up, you partition your disk
> >>> provided by xen dom0 (Debian), chroot, unpack stage3 and install the
> >>> system along with the kernel and a bootloader. You can boot your
> >>> Gentoo with pvgrub that will handle the booting to grub and it will
> >>> load the kernel. This way, the Gentoo machine is like a black box for
> >>> your Debian.
> >>>
> >>> I would recommend starting with HVM.
> >>
> >> Hm, I haven't used HVM yet.  Can I change over to PV after the
> >> installation is done?  What's the advantage of starting with HVM?
> >>
> >> The "disk" is an LVM volume and won't be partitioned.  I've found it
> >> more reasonable to use a separate LVM volume for swap.
> >>
> >> I never installed Gentoo.  I could start with my desktop since I
> >> want to
> >> replace Fedora anyway.  That's a bit troublesome because I either have
> >> to plug in some disks for it which I'd need to buy first (I might get
> >> two small SSDs), or I'd have to repartition the existing ones.
> >>
> >> Hmmm.  I think I'll try a VM with PV first.  If that doesn't work, no
> >> harm is done and I can still ask when I'm stuck.
> >>
> >>
> >> Oh I almost forgot: Does the VM need internet access during the
> >> installation?  The network setup is awfully complicated in this case.
> >
> > Well, you can copy the files to another place, but I have never done
> > this transformation. HVM is like a black box, you start like booting a
> > normal machine. For production, I always use PV, but for starters, HVM
> > is also fine.
>
> So you cannot easily change from HVM to PV?

You can, but then you need to ensure the install has both the PV as well as 
the HVM drivers installed and can switch between them easily.

> > Yes, you will need internet access because we compile everything as it
> > goes, so you need to download the source files. Or, maybe you can
> > download a livedvd, but I've never tried that.
> >
> > Why is the networking complicated? Do you use bridging?
>
> Yes --- and it was terrible to begin with and still is very complicated.
> One of the VMs has a network card passed through to do pppoe for the
> internet connection, and it also does routing and firewalling.  The
> Gentoo VM is supposed to have another network card passed through
> because I want a separate network for miscellaneous devices like IP
> phones and printers.  Asterisk is going to run on the Gentoo VM.

This sounds convoluted. Why add to the complexity by adding multiple network 
cards into the machine and pass the physical cards?

> Besides devices, there's the usual net, dmz and loc zones.  To top it
> off, sooner or later I want to pass another network card to the
> firewall/router because I have an internet connection which is currently
> not in use and should be employed as an automatic fallback.

How many cards are you planning on having in the machine?
Are all these connected to the same switch?

--
Joost