virt June 2014

virt@lists.centos.org

38 participants
28 discussions

Finally switching from Xen to KVM - question about networking
by Steve Campbell 11 Jun '14

11 Jun '14

I had so much trouble putting Centos 6 guest VMs on a Centos 5 host that I finally switched to a Centos 6 host. I've not needed more that test VMs, so I've used Virtual Machine Manager on the old system, which worked pretty well, so I decided to create my first KVM guest machine. I noticed when I created it, I only had the options of NAT for my network interface, so I used that (obvious). Well, after starting the VM, I find I don't have connectivity with that interface. Reading, I find examples where I need to create bridges perhaps. Xen did most of this for me, so it's a little new to me. Can anyone throw me a clue, please? steve campbell

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Re: [CentOS-virt] qemu-kvm rebuild in Centos for oVirt in SIG Virt
by George Dunlap 10 Jun '14

10 Jun '14

On Tue, Jun 10, 2014 at 5:18 PM, Karanbir Singh <kbsingh(a)centos.org> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On 06/10/2014 05:16 PM, George Dunlap wrote: >> >> They seem keen to get this in sooner rather than later. Is there >> yet a way for me to create a new package for the Virt SIG that you >> could brief me on? Alternately, could one of the core CentOS team >> take a bit of time sometime in the next few weeks to build such a >> package? >> >> I tried to build the qemu-kvm package on git.centos.org, hoping to >> be able to just give you guys a functional repo you could use, but >> the c6 branch of the repo on git.centos.org seems to be empty. > > we are hoping to boot the community buildsystem up in the coming days, > that would be the best place to handle this. Excellent -- looking forward to it. > also, the virt-sig repo setup at this point is the xen4centos repo - > is that the best place to land this ? Well I guess we have two options: 1. Rename xen4centos to sigvirt-hv (or something like that -- Virt SIG, hypervisor level) 2. Create a new repo for qemu changes (kvm4centos? sigvirt-kvm?) On a practical level, this only affects the (I'm guessing) fairly small number of people who install two different hypervisors. For those people, #1 means opting into all the Virt SIG hypervisors when opting into one, and having to do something special to get the upstream version of one and the Virt SIG version of another; while #2 means opting into each Virt SIG hypervisor separately. I suppose #1 would mean automatically getting for updated ancillary packages from xen4centos (ocaml?) when you just wanted to install qemu-kvm. Choosing #2 may mean a proliferation of repos; but since there will almost certainly never be more than 4 different hypervisors supported, that's probably not too big of an issue. I'm not sure what else it might mean from a technical perspective. Anything I missed? I don't really have strong opinions here. My personal inclination would be to just have one repo; but I could see how it might be weird to accidentally get updated packages related to Xen when you just wanted snapshotting for KVM. -George

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Re: [CentOS-virt] qemu-kvm rebuild in Centos for oVirt in SIG Virt
by Douglas Schilling Landgraf 10 Jun '14

10 Jun '14

On 06/05/2014 07:22 AM, George Dunlap wrote: > On Thu, Jun 5, 2014 at 11:25 AM, Lars Kurth <lars.kurth(a)xen.org> wrote: >> On 04/06/2014 20:17, Douglas Schilling Landgraf wrote: >>> Hello, >>> >>> I would like to continue this process in the SIG Virt. Any advice/steps >>> which I should follow? >>> >>> Thanks! >>> >> Douglas, >> we are not ignoring you. As it turns out there are quite a few unknown >> pieces related to the libvirt version for this SIG and there was also a >> discussion with Dan Kenigsberg at last week's Hackathon. I don't have >> the technical depth to go through your proposal. Added George. > > So the problem at the moment is that the CentOS project is still in > transition to being community-developed. Lars and I are officially > running the SIG, but we don't yet have a way to create new packages > for our SIG; and the core CentOS team is rather overwhelmed with > trying to develop and set up this new system, manage all the SIGs, and > prepare for CentOS 7. > > So, rest assured that "create a qemu-kvm package with snapshot > enabled" is on our to-do "short list", and won't be forgotten; but it > may be a few months before the system is in place for non-core CentOS > people to contribute new packages. > > If you think this needs to happen sooner for some reason, we'll > probably need to ask KB or Johnny to do it. > > -George > Thanks for the feedback George and Lars. As we have several users requesting such feature and there is a new oVirt release knocking the door I would like to continue with KB or Johnny. -- Cheers Douglas

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Network Bridgeing
by Ing. Ramon Resendiz 10 Jun '14

10 Jun '14

Hi, I have the following issue i recently installed a VM with qemu and libvirtd, everything is almost ok. The problem is that i have 5 usable IP address (valid ip address on internet) for eth0, and i want to use one of this IP for my VM (Windows 2008 Standard R2 by the way). I did the bridge between my eth0 and br0, the VM could browse into internet and download patches, etc. etc. I tried to use a networking alias, this is the network interface eth0 assign a IP address and for the eth0:1 assign other IP address, and this bridged to the br0 instead of eth0 to eth0:1; after restart the network service the connectivity lost, and then get in back the original configuration everything seems to work again. But my goal is not archived. Goal: eth0 must have a valid ip address to be accesed, eth0:1 (bridged to br0) must have a valid address to be assigned to the VM. Through iptables assign ACL to each IP address (valid IP address) depending of the services to host (web server and db server, rdp host) and between interfaces could be possible to communicate between them (virtual host and virtual machine). eth0: Virtual Host eth0:1: Virtual machine (bridged to br0) Thank you very much for you time. Best regards, RR

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Problem with X on VM
by Steve Campbell 09 Jun '14

09 Jun '14

I've got a Centos 5 server with Xen installed. I'm trying to install a Centos 6.5 VM on it but once all is installed, the X window will not sync or display. I think I understand that it's probably due to the settings on the vnc stuff. I've got Centos 6.2 VMs that act just fine. Is there a way I can modify the VM's screen settings either during installation or after installation? Hope that makes sense. Thanks steve campbell

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Re: [CentOS-virt] Windows 7 on a centos kvm host pauses after the installation reboot.
by James B. Byrne 09 Jun '14

09 Jun '14

On Sun, June 8, 2014 19:21, Eliezer Croitoru wrote: > I am using Centos 6.5 as a kvm hypervisor with local ssd disks in raid > and with glusterfs based storage for couple disk images. > I have tried to install Windows 7 from ISO and it seems to pass the > first stage of the installation which installs the basic files and also > the first reboot. > After that the installation is almost finished and the desktop should be > up and running after a reboot but instead the Windows 7 machine gets > paused before windows shows the windows 7 logo at the boot sequence. > > I have tried to find for a record of the issue in the past but found > only tiny records which I did not understood from, if it was solved or not. > The kvm host has 16GB of ram and 100GB of disk space. > For this specific host I have used a disk image ontop of glusterfs but > the same happens ontop of glusterfs and ontop of local disks. > > I have an ubuntu kvm host with less RAM and I can install windows server > 2012 (which I was unable to install on the Centos 6.5 kvm host both 2012 > + windows 8 + windows 7). > > Two things: > If anyone had or has the same issue please notify me. > If anyone has a solution please share it. > > Thanks, > Eliezer > 1. Is there a CD/DVD drive associated with the VM? 2. If so, do you have a readable optical disk in the drive when starting the Windows7 guest? If the answer to 1 is yes and to 2 is no and your guest configuration file shows this: 30 <disk type='block' device='cdrom'> 31 <driver name='qemu' type='raw'/> 32 <source dev='/dev/sr0'/> 33 <target dev='hdc' bus='ide'/> 34 <readonly/> 35 <address type='drive' controller='0' bus='1' target='0' unit='0'/> 36 </disk> then remove the line '<source dev='/dev/sr0'/>' and try again. HTH. -- *** E-Mail is NOT a SECURE channel *** James B. Byrne mailto:ByrneJB@Harte-Lyne.ca Harte & Lyne Limited http://www.harte-lyne.ca 9 Brockley Drive vox: +1 905 561 1241 Hamilton, Ontario fax: +1 905 561 0757 Canada L8E 3C3

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Windows 7 on a centos kvm host pauses after the installation reboot.
by Eliezer Croitoru 08 Jun '14

08 Jun '14

I am using Centos 6.5 as a kvm hypervisor with local ssd disks in raid and with glusterfs based storage for couple disk images. I have tried to install Windows 7 from ISO and it seems to pass the first stage of the installation which installs the basic files and also the first reboot. After that the installation is almost finished and the desktop should be up and running after a reboot but instead the Windows 7 machine gets paused before windows shows the windows 7 logo at the boot sequence. I have tried to find for a record of the issue in the past but found only tiny records which I did not understood from, if it was solved or not. The kvm host has 16GB of ram and 100GB of disk space. For this specific host I have used a disk image ontop of glusterfs but the same happens ontop of glusterfs and ontop of local disks. I have an ubuntu kvm host with less RAM and I can install windows server 2012 (which I was unable to install on the Centos 6.5 kvm host both 2012 + windows 8 + windows 7). Two things: If anyone had or has the same issue please notify me. If anyone has a solution please share it. Thanks, Eliezer

1 0

Network Bridgeing
by Ing. Ramon Resendiz 08 Jun '14

08 Jun '14

1 0

Xen Security patching
by Chris Elliott 07 Jun '14

07 Jun '14

Hi Guys When is the next update of Hypervisor packages going to be released? There appears to be no changes to the main hypervisor RPMs since September (Even in the BETA / RC1 tree) and there are 5+ Xen Security Advisories with patches which need to be added. "Security issues are handled and released in sync with public disclosure upstream with zero lag" I can rebuild my own, but that's not really the point. In other news I've been doing some testing of the 3.10 kernel and so far so good! Thanks - Chris

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xen setup documentation for centos?
by lee 07 Jun '14

07 Jun '14

Hi, what is the proposed way to create domU guests on centos 6.5? At first I tried to follow the documentation on the xen project website which recommends using xl. I created a config file and ended up with getting a message that the kernel is not bootable when trying to create a guest. I also had to stop some daemon (xend?) because it said that xl isn`t compatible with it and the daemon must be stopped first. Then I followed redhat documentation which suggests to use virt-manager --- which doesn`t work because servers don`t have GUIs. So I finally managed to create a guest with virt-install. I can start and stop the guest (which is also running centos), though I don`t think this is the right way to create one. So how exactly are you supposed to create guests? Now I can`t get the networking to work. I`ve been reading lots of documentation and still don`t understand how that is supposed to work. As far as I understand, you get three different network interfaces: dom0: a bridge (virbr0) dom0: a virtual network interface (vifN.X) domU: a virtual network interface which doesn`t appear to be virtual to domU And dom0 keeps it`s own network interface(s), like eth0, which is a physical one. Is vifN.X the same as eth0 in domU? Or what is it for? If it`s the same, is it supposed to have the same IP on both sides? How do I make it so that domU has network access (beyond dom0)? How does this network stuff work? Do the virtual devices have to be in different subnets? When they are not, the network becomes reachable via multiple interfaces, and I`m guessing that either packet loops may be created or some paths might be disabled by STP. Do I have to set up shorewall (or the like) on dom0 to be able to handle network access for guests? Would I need to create a bridge for every guest to be able to handle them separately for firewalling purposes because otherwise packets circumvent firewall rules by directly going over the bridge? If so, why are bridges needed? I would understand doing things like adding those guests that are visible to the LAN only to the same bridge to have them all reachable likewise. When doing that, it would seem to make sense to use a different subnet for guests in the DMZ. All the documentation tells you many different things, none of them work and it`s totally confusing. Is there any /good/ documentation somewhere? -- Knowledge is volatile and fluid. Software is power.

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virt June 2014