Amahi Guest OS - XEN Source

[lou1z]

hi nuclear216,
esxi (free) is a little different than esx (costs)
to get the same functionality on esxi, you have to pay for the extras. esxi is small and fussy (storage & nic's) as to what it installs on compared to a full blown esx. xen has much more functionality for free. not sure about the hosts compatibility but the last time i looked, xen wasn't near as good as vmware.
vmware will run just about anything (not sure about osx)
i have fedora's, cento's, ubuntu's, openfilers yada yada as well as all flavours of windows running under it. to get the most you have to install vmware tools which can be a little painful under linux as there are a few dependancies required.
as for managing it once its installed, unfortunetely you need a seperate windows machine to get the most out of it.
you can run it from the cli under linux and you can also do a hack to ssh into the console.

[nuclear216]

So they're both bare metal hypervisor with different underlying technology (still both ok for home use) and different licensing models.
I like xenserver (free) network and storage config, you can do pretty much whatever you want, any VLAN config included.

It misses email-alerts and some advanced logging functionality, they sell you this and the app to manage many server at once on high availability and network balancing, for one server and N virtual machine is all there, backup, ssh etc.
I am not sure about guest support because they only officially support paravirt redhat/centOs/Debian but with hardware virt any linux could be installed unmodified, I can't try it so I am can't speak about that.
The xs-tools installed just fine on supported guests , don't know for unsupported ones.

this guy here http://www.isaaczarb.com/templates/ is making his own template for ubuntu.
It's the only clean way to install one's own paravirt linux, 3rd party sells those for datacenter OSes other than those supported by citrix.
But it looks feasible to write one, I am going with this.

[nuclear216]

Hi,
I was able to get a PV fedora template to use a fedora VM in xenserver, the thing is in order to boot this VM I need to create an initrd boot image pygrub and xen compatible for the stock kernel (which support booting as domU guest, so no recompiling was needed).

Fedora uses dracut to do that, which I don't know at all, I am reading about it but it's a completely new system!

I should remove scsi modules (which causes trouble with xen) and load xenblk and xennet modules (which I also suppose should already be there)

How do I do that with dracut?

here's the usual command

Code: Select all

initrd --omit-scsi-modules --with=xennet --with=xenblk --preload=xenblk initrd.img currentkernel

[nemolomen]

Hi nuclear316,

I too have been looking into virtualizing my amahi server through XEN but have not done so because Fedora 12 does not have a precompiled fully virtualized kernel. Last I knew, Fedora project states no paravitualization until at least F13 as they are waiting for upstream changes.

For now I have been dabbling with KVM, which will allow hardware vitualization. And, since my server box is Phenom X3 w/4 GB RAM, I can play with it. Not sure if KVM will work with Atom since Atom does not have hardware virtualization support.

I also found out recently that virtualized networking, even with dedicated hardware (a second NIC), can be a bit tricky under KVM. As an exercise, I tried to install a simple Wolfenstein: Enemy Territory server under F9(i386) in a KVM VM the other day. Spent all day (6 hours) and it still did not work and since the opportunity for use is gone now, I probably won't go back to see if I can fix it.

[nuclear216]

Hi nemolomen,

doesn't seems that way to me, see fedora 12 release note, maybe they were able to squish it in at the last moment or you meant dom0 (fedora as Xen hostOS)?

5.3.12.3. Xen Kernel Support
The kernel package in Fedora 12 supports booting as a guest domU, but will not function as a dom0 until such support is provided upstream. Work is ongoing and hopes are high that support will be included in kernel 2.6.33 and Fedora 13.
The most recent Fedora release with dom0 support is Fedora 8.

and here more about it
http://fedoraproject.org/wiki/Features/XenPvops

See also this for playing with HVM to PV conversion under Xenserver
http://itproctology.blogspot.com/2009/0 ... erver.html

I've hit some boot issues in doing all this on a fedora 12 domU and than I enjoyed the party (a hard one this year ) so I wont be able to immerse myself again in linux paravirt issues for a few days...


btw if you plan to use VM for games I'd suggest the "ice" version of the well known OS within Virtual Box, the NON open source version has a 3d driver which works great for games like that (or AoE/AoM), not the latest one since maximum RAM is too limited, but still, you could end up with a bunch of VM all containing different sets of games pre-installed and configured, it's actually very handy. no issues like networking neither stability or compatibility, the non-OSS version is precompiled with hardware extension support so even if you don't have virt on your chip it thinks so and let you install windows, oddly enough it works decently.