June 2014 - virt - lists.centos.org

KVM integrated network (user mode) dying after inactivity
by Timo Schöler 03 Aug '14

03 Aug '14

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Hi list, I searched the web for bug reports regarding this phenomenon I see on *multiple* machines of a customer, however, I didn't find an exact fit. So, I'd like to ask here whether anyone else has run into this. I have multiple CentOS 6 machines running using KVM to virtualize a bunch of machines on them (LVM-based). Software releases as following: [root@fe00 ~]# rpm -qa|egrep '(virt|kvm)' virt-viewer-0.5.6-8.el6_5.3.x86_64 libvirt-python-0.10.2-29.el6_5.7.x86_64 libvirt-client-0.10.2-29.el6_5.7.x86_64 qemu-kvm-0.12.1.2-2.415.el6_5.8.x86_64 libvirt-0.10.2-29.el6_5.7.x86_64 python-virtinst-0.600.0-18.el6.noarch [root@fe00 ~]# uname -r 2.6.32-431.17.1.el6.x86_64 The VMs (here: two) have the "default" connection provided by KVM (heading to the internet) as well as a bridged interface to connect to a high performance backbone, where sensitive data is kept and bandwidth is an issue (or better, not :), on a second interface within the VMs: [root@fe00 ~]# brctl show bridge name bridge id STP enabled interfaces br1 8000.001b21xxxxxx yes eth1 vnet1 vnet3 virbr0 8000.525400xxxxxx yes virbr0-nic vnet0 vnet2 br1 is the interface connected to the backbone, virbr0 KVM's user mode network. After some time of inactivity on the virbr0 interface, from *within* the VMs connection is *lost*. The interface(s) lose their IP; running dhclient(8) is not of any use. To get the machine back onto track, ``service libvirtd restart'' has to be issued: Vanished iptables rules show up again. (This, in contrast to an Ubuntu document [0], fixes it without shutting the VM(s) down.) Starting dhclient(8) within the VMs gets connectivity back. Just out of curiosity I let one of the VMs cause some ICMP traffic now and then hit the interface -- ``ping -i 10 some.nice.host'' is sufficient to keep that interface alive. The virbr0-headed interfaces are almost only being used to get updates etc -- management and load-balanced services are being served by the bridged interface. Is this a bug or a feature? Best, Timo [0] -- https://help.ubuntu.com/community/KVM/Networking#Network_Bridge_Losing_Conn… -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iF4EAREIAAYFAlOPaBgACgkQuSPmkPhAW0r9lgD/cgsDSxaOlD150DLbF+PIGjS7 3qSv3rob7NQEz4wJkUIA/1KfjLmCGm1y2LLroFsWbfckTnDfN3LSG1sUNvygLB/C =ZhOI -----END PGP SIGNATURE-----

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[ Off Topic ] WorkShop Virtualização com Proxmox VE
by Gilberto Nunes 30 Jun '14

30 Jun '14

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Re: [CentOS-virt] MS-Win7 kvm guest gets dhcp from host bridge
by James B. Byrne 23 Jun '14

23 Jun '14

On Mon, June 23, 2014 00:29, Arun Khan wrote: > On Thu, Feb 20, 2014 at 3:36 AM, Dusty Mabe <dustymabe(a)gmail.com> wrote: >> >> On 02/19/2014 04:01 PM, James B. Byrne wrote: The root cause of the original problem was a change in the behaviour of libvirt (and the GUI of virt-manager) when creating new vms. The host system was already bridged and had other vms previously created and attached to the bridge without exhibiting this behaviour. I infer that at some point an update to libvirt altered the default configuration to always prefer NAT. A change that I failed to notice and was not conscious of given I had previous created vms without encountering this problem. Changing the configuration of the affected vms nic Source Device to 'Specify shared device name' and then specifying the Bridge Name fixed the problem. I have already commented elsewhere on the needlessly obtuse wording used for the Source Device when bridging is required. Why it does not say 'Specify bridge name' or 'Use named bridge' instead has not been plausibly explained by the maintainers. It is particularly vexatious given that when one selects 'Specify shared device name' the GUI immediately alters to display a text box labelled 'Bridge name:' Duhhh. -- *** 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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MS-Win7 kvm guest gets dhcp from host bridge
by James B. Byrne 23 Jun '14

23 Jun '14

CentOS-6.5 i86_64 qemu-kvm-0.12.1.2-2.415.el6_5.4 MS-Windows v7proSP1 We have installed a MicroSoft Win7 system as a guest and have joined it to our MS AD domain. The system runs and has internet access. However, the IPv4 address it obtains and the gateway it is assigned are both sourced from the virtual machine host system and not from our AD DC DHCP server. To clarify, the virbr0 IP address is 192.168.122.1 and the Windows guest has that address as its gateway and an IP address in the 192.168.122.0/24 netblock. This is not as we desire as the internal addresses we regularly assign to MS workstations via DHCP are supposed to belong to a different netblock entirely. This permit filtering on incoming and outgoing traffic at the gateway. I realize that there is a DHCP service running on virbr0 for the purpose of provisioning guests with system control traffic but I do not know how to limit that to its intended purpose and allow another DHCP server to provide the IP address to the windows guests. I hope that problem description is not too confusing. Can anyone provide me with some guidance on the matter? Are kvm guests required to have either static ip addresses or dhcp addresses provided by the host system? Thanks in advance. -- *** 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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Preferred method of provisioning VM images
by Lars Kurth 20 Jun '14

20 Jun '14

Hi all, following the discussion on about documentation, I was wondering whether we need to look at a standard way in which we recommend how to provision images for VMs. Am starting this with a Xen hat, but the discussion should not be specific to this. There are a number of options, but all have some trade-offs == #1 virt-install == Advantages: similar to KVM Disadvantages: may cause weird issues / confusion with people switching back to xl. The core issue is that with the current version of xen and libvirt, this only works with xm (when xl is used, this can create some undefined behavior). However as we have seen in some recent threads on this list, people tend to mix which can cause problems. == #2 xen-tools == Advantages: Very flexible. Many other distros use xen-tools, so we have lots of beginners docs that just need to be tweaked Disadvantages: needs porting/packaging for CentOS. Does not work for kvm. Says "xen". (Maybe that's an advantage.) We know that xen-tools works with Fedora (see http://blog.xen.org/index.php/2013/01/24/using-xen-tools-on-fedora/) so the porting effort may be small Unknowns: What would be needed to make it work for CentOS == #3 virt-builder (http://libguestfs.org/virt-builder.1.html) == Advantages: supports KVM, Xen and other VM inages. Seems easy to use. - if so, it would avoid xm / xl confusion. Unknowns: Not sure at which level virt-builder integrates with Xen and other hypervisors. It seems to operate at disk image format (similar to xen-tools) . I don't know whether virt-builder is restricted to some hypervisors in RHEL7. Disadvantages: may need porting/packaging for CentOS. It appears as if it will be in RHEL7, so it may just appear with CentOS 7. If not, some porting work may need to be done. == #4 Cloud Image from Cloud Image SIG == We could rely on pre-built cloud images from the Cloud Images SIG. People could just download the cloud image once it's done and customize it, rather than installing / building their own. Advantages: seems easy Disadvantages: coordination with Cloud Images SIG. May not be flexible enough I just wanted to start a discussion about this and ask for input. This topic which has come up a number of times in SIG meetings as a facgtor influencing libvirt and other package versions. Regards Lars

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How to create an OpenVZ OS Template for CentOS 7 Public QA
by Scott Dowdle 17 Jun '14

17 Jun '14

Greetings, First start of by working on a physical system, virtual machine, or container that matches the OS Template you are wanting to build. I used my CentOS 7 Public QA OS OpenVZ container to build it. You must of course have a working yum. Once we are beyond Public QA and there is stuff in /etc/yum.repos.d/ this won't be a problem. One thing to note is that the --enablerepo= must refer to a repo your build host has and viewable via "yum repolist". That repo should point to the desired CentOS 7 build tree directory. A note about the package list. Yes, listed out every individual packcage is tedious. Perhaps some package groups could be used but they typically drag in a lot of unwanted additional packages. Suggestions welcome. Here is a simple script and please don't nag at me because I'm a scripting novice. I hope email client word wrapping and screen sizes don't butcher it too bad: - - - - - # To get a package list without version numbers from a target system # rpm -qa --qf "%{n} " > packages.txt # Put contents of packages.txt after "-y install \" line below mkdir /ostemplate yum \ --installroot /ostemplate \ --nogpg \ --releasever=7 \ --enablerepo=centos7pubqa \ -y install \ centos-release filesystem ncurses-base mailcap tzdata glibc-common xz-libs \ ncurses-libs pcre libselinux info libdb popt sed libcom_err libuuid expat \ libacl libgpg-error dbus-libs gawk lua libxml2 glib2 shared-mime-info apr cpio \ gmp p11-kit tcp_wrappers-libs perl-parent perl-podlators perl-Text-ParseWords \ perl-Pod-Escapes perl-libs perl-threads perl-constant perl-Filter \ perl-Time-Local perl-threads-shared perl-File-Path perl-Scalar-List-Utils \ perl-Getopt-Long libcap-ng nss-softokn libassuan libunistring diffutils gpm-libs \ libnfnetlink keyutils-libs gettext-libs p11-kit-trust nettle \ gobject-introspection vim-minimal pinentry make libselinux-utils ncurses \ libverto libsemanage krb5-libs openldap cracklib libmount systemd-libs libuser \ pam libblkid util-linux python-libs dhcp-libs libcurl python-urlgrabber rpm-libs \ dhcp-common libselinux-python python-iniparse python-chardet yum-metadata-parser \ python-backports-ssl_match_hostname newt-python pyxattr binutils logrotate \ procps-ng mariadb-libs fipscheck-lib openssh libmnl iptables json-c \ device-mapper cryptsetup-libs dbus iputils cronie-anacron crontabs libestr \ gnupg2 rpm-python pygpgme libnl3 yum-utils man-db dhclient audit openssh-server \ libgudev1 net-tools elinks python-pyudev policycoreutils python-configobj \ pygobject3-base sudo wget file tar which psmisc libpcap libsysfs libdaemon lzo \ libgcc setup basesystem kbd-misc bind-license nss-softokn-freebl glibc libstdc++ \ bash libsepol zlib audit-libs nspr chkconfig bzip2-libs nss-util grep libattr \ libcap elfutils-libelf libgcrypt readline libidn libffi pkgconfig sqlite \ groff-base file-libs libtasn1 slang gdbm perl-HTTP-Tiny perl-Pod-Perldoc \ perl-Encode perl-Pod-Usage perl-macros perl-Storable perl-Carp perl-Exporter \ perl-Socket perl-File-Temp perl-PathTools perl-Pod-Simple perl apr-util libcroco \ cyrus-sasl-lib libgomp kmod-libs libedit hostname js newt ca-certificates less \ dbus-glib acl libdb-utils findutils xz sysvinit-tools ustr nss-tools \ openssl-libs gzip cracklib-dicts nss libpwquality coreutils shadow-utils \ libutempter nss-sysinit python libssh2 python-pycurl curl rpm python-decorator \ python-slip dbus-python python-kitchen python-backports python-setuptools \ pyliblzma centos-logos kmod openssl nss_compat_ossl bind-libs-lite fipscheck \ httpd-tools libnetfilter_conntrack iproute qrencode-libs device-mapper-libs \ systemd systemd-sysv initscripts cronie libpipeline pth rpm-build-libs gpgme yum \ libnl3-cli rsyslog mlocate kbd postfix httpd ebtables openssh-clients authconfig \ python-slip-dbus mc gettext screen passwd gnutls elfutils-libs libss nano snappy \ libndp ethtool hardlink rootfiles ln -sf /proc/mounts /ostemplate/etc/mtab # I want Mountain time to be the default ln -sf /usr/share/zoneinfo/America/Denver /ostemplate/etc/localtime # Now compress that sucker cd /ostemplate ; tar -cvJf /root/centos-7-x86_64-viayum.tar.xz . ; cd ls -lh /root/centos-7-x86_64-viayum.tar.xz echo "Done building OS Template. Now test it." - - - - - TYL, -- Scott Dowdle 704 Church Street Belgrade, MT 59714 (406)388-0827 [home] (406)994-3931 [work]

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Are xen and centos incompatible?
by lee 17 Jun '14

17 Jun '14

Hi, I'm trying to pass a physical network interface through to a domU. This seems to be impossible because the way xen wants to do it is incompatible with the way centos wants to do it. I followed documentation on http://www.xen-support.com/?p=151 and tried booting with 'pciback.permissive pciback.hide=(06:00.0)'. This gives a hint in dmesg "kernel: xen-pciback: backend is vpci", and the device is still visible in dom0. So this obviously doesn't work. Following http://wiki.xen.org/wiki/Xen_PCI_Passthrough: [root@heimdall ~]# xl pci-assignable-add 06:00.0 xend is running, which may cause unpredictable results when using this xl command. Please shut down xend before continuing. (This check can be overridden with the -f option.) [root@heimdall ~]# There doesn't seem to be any documentation about what xend does or is for and how to pass a physical network interface through with it. I'm starting to think that using centos for a server os is an extremely bad choice because nothing works. It's not like a Linux distribution but like a mess of pieces from several unrelated puzzles thrown together randomly. -- Knowledge is volatile and fluid. Software is power.

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Centos 6.5 Xen Stock cannot run dom-u PCI: Fatal: - ipmi_si
by Periko Support 17 Jun '14

17 Jun '14

I had a supermicro server SuperServer 1027R-WRF4+ and a old Dell PowerEdge 2950. In both machines I setup centos 6.5, which is running 3.10.34-11.el6.centos.alt.x86_64. I follow Xen4Cen wiki to setup Xen, I had other servers running Centos 5.x without issues. Now, once I build my vm's dom-u centos 6.5/centos 5.9 both x64, I receive different erros, let me show u the message I receive in my console for centos 6.5 dum-u. xl console oerp-server PCI: Fatal: No config space access function found ipmi_si: Could not set up I/O space ipmi_si: Could not set up I/O space ipmi_si: Could not set up I/O space Something related to ipmi in my server which is enable by default? can be, now what happen is I try to boot xentos 5.9 x64 dom-u: Brought up 1 CPUs checking if image is initramfs... it is Grant table initialized NET: Registered protocol family 16 Brought up 1 CPUs PCI: setting up Xen PCI frontend stub ACPI: Interpreter disabled. Linux Plug and Play Support v0.97 (c) Adam Belay pnp: PnP ACPI: disabled xen_mem: Initialising balloon driver. usbcore: registered new driver usbfs usbcore: registered new driver hub PCI: System does not support PCI PCI: System does not support PCI NetLabel: Initializing NetLabel: domain hash size = 128 NetLabel: protocols = UNLABELED CIPSOv4 NetLabel: unlabeled traffic allowed by default NET: Registered protocol family 2 IP route cache hash table entries: 65536 (order: 7, 524288 bytes) TCP established hash table entries: 262144 (order: 10, 4194304 bytes) TCP bind hash table entries: 65536 (order: 8, 1048576 bytes) TCP: Hash tables configured (established 262144 bind 65536) TCP reno registered audit: initializing netlink socket (disabled) type=2000 audit(1402907331.494:1): initialized VFS: Disk quotas dquot_6.5.1 Dquot-cache hash table entries: 512 (order 0, 4096 bytes) Initializing Cryptographic API alg: No test for crc32c (crc32c-generic) ksign: Installing public key data Loading keyring - Added public key 691B840A64868995 - User ID: CentOS (Kernel Module GPG key) io scheduler noop registered io scheduler anticipatory registered io scheduler deadline registered io scheduler cfq registered (default) pci_hotplug: PCI Hot Plug PCI Core version: 0.5 rtc: IRQ 8 is not free. Non-volatile memory driver v1.2 Linux agpgart interface v0.101 (c) Dave Jones brd: module loaded Xen virtual console successfully installed as xvc0 Event-channel device installed. Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2 ide: Assuming 50MHz system bus speed for PIO modes; override with idebus=xx ide-floppy driver 0.99.newide usbcore: registered new driver hiddev usbcore: registered new driver usbhid drivers/usb/input/hid-core.c: v2.6:USB HID core driver PNP: No PS/2 controller found. Probing ports directly. i8042.c: No controller found. mice: PS/2 mouse device common for all mice md: md driver 0.90.3 MAX_MD_DEVS=256, MD_SB_DISKS=27 md: bitmap version 4.39 TCP bic registered Initializing IPsec netlink socket NET: Registered protocol family 1 NET: Registered protocol family 17 XENBUS: Device with no driver: device/vbd/51712 XENBUS: Device with no driver: device/vif/0 XENBUS: Device with no driver: device/console/0 Initalizing network drop monitor service Write protecting the kernel read-only data: 506k Red Hat nash version 5.1.19.6 starting Mounting proc filesystem Mounting sysfs filesystem Creating /dev Creating initial device nodes Setting up hotplug. Creating block device nodes. Loading ehci-hcd.ko module Loading ohci-hcd.ko module Loading uhci-hcd.ko module USB Universal Host Controller Interface driver v3.0 Loading jbd.ko module Loading ext3.ko module Loading xenblk.ko module XENBUS: Waiting for devices to initialise: 295s...290s...285s...280s...275s...270s...265s...260s...255s...250s...245s...240s...235s...230s...225s...220s...215s...210s...205s...200s...195s...190s...185s...180s...175s...170s...165s...160s...155s...150s...145s...140s...135s...130s...125s...120s...115s...110s...105s...100s...95s...90s...85s...80s...75s...70s...65s...60s...55s...50s...45s...40s...35s...30s...25s...20s...15s...10s...5s...0s... XENBUS: Timeout connecting to device: device/vbd/51712 (local state 3, remote state 1) Loading dm-mod.ko module device-mapper: uevent: version 1.0.3 device-mapper: ioctl: 4.11.6-ioctl (2011-02-18) initialised: dm-devel(a)redhat.com Loading dm-log.ko module Loading dm-mirror.ko module Loading dm-zero.ko module Loading dm-snapshot.ko module Loading dm-mem-cache.ko module Loading dm-region_hash.ko module Loading dm-message.ko module Loading dm-raid45.ko module device-mapper: dm-raid45: initialized v0.2594l Scanning and configuring dmraid supported devices Scanning logical volumes Reading all physical volumes. This may take a while... No volume groups found Activating logical volumes Volume group "VolGroup00" not found Creating root device. Mounting root filesystem. mount: could not find filesystem '/dev/root' Setting up other filesystems. Setting up new root fs setuproot: moving /dev failed: No such file or directory no fstab.sys, mounting internal defaults setuproot: error mounting /proc: No such file or directory setuproot: error mounting /sys: No such file or directory Switching to new root and running init. unmounting old /dev unmounting old /proc unmounting old /sys switchroot: mount failed: No such file or directory Kernel panic - not syncing: Attempted to kill init! Looks is not finding the dom-u disk. In both cases I'm using almost the same settings: name = "centos5" uuid = "5020979f-8dae-105d-df56-9fb28d377aa2" bootloader = "/usr/bin/pygrub" memory = 2048 on_poweroff = "destroy" on_reboot = "restart" on_crash = "restart" disk = [ "tap:aio:/ext4/centos5/disk.img,xvda,w" ] vif = [ "mac=X:X:X:X:X:X,bridge=xenbr0,script=vif-bridge" ] The main line of centos stock without Xen continue using kernel 2.6.x, but Xen is using the new line 3.x. Anyone else with this issue? Thanks for your time.

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Re: [CentOS-virt] [Xen-users] Can't get vnc connections to bind to 0.0.0.0
by Periko Support 17 Jun '14

17 Jun '14

On Tue, Jun 17, 2014 at 7:47 AM, Ian Campbell <Ian.Campbell(a)citrix.com> wrote: > On Tue, 2014-06-17 at 10:41 -0400, Phillip Susi wrote: >> On 6/17/2014 10:10 AM, Ian Campbell wrote: >> > Which toolstack. >> >> xl >> >> > This is a PVFB, not sure if they work for HVM or not. >> >> Seems to work just fine other than refusing to bind to 0.0.0.0 so I >> can access it from another machine on the network without setting up >> an ssh tunnel. >> >> > You probably want a toplevel vnclisten="0.0.0.0:0" to cause the >> > VNC associated with the emulated VGA to be bound to the address >> > which you want. >> >> "toplevel"? > > I mean literally write: > vnclisten="0.0.0.0:0" > in your configuration file, not wrapped in a vfg = []. > > Ian > > > _______________________________________________ > Xen-users mailing list > Xen-users(a)lists.xen.org > http://lists.xen.org/xen-users This is my settings: vfb = [ "type=vnc,vnclisten=192.168.2.27,vncpasswd=XXXXXX,vncdisplay=1,keymap=en-us" ] Hope this helps.

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Xen PV domU reported as Xen-HVM
by Karl Johnson 17 Jun '14

17 Jun '14

Hello, I am running two dom0s, one on CentOS 5 with Xen 4.1.2 (from Gitco) and the other one on CentOS 6 with Xen 4.2.4 (from Xen4CentOS). I host one LVM based domU on both from the same template (CentOS 6 PV) with the same Xen config (see below). However, the domU on Xen 4.1 reports itself as Xen PV while the domU on Xen4CentOS reports itself as Xen HVM. == First domU == virt-what and cPanel scripts report domU as: xenpv dom0: 2.6.18-371.6.1.el5xen Xen 4.1.2 domU Config: bootloader = '/usr/bin/pygrub' extra = '' memory = 6144 hostname = 'web2.x.ca' cpu_weight = 256 name = 'vm115' vif = ['ip=205.X.X.X, vifname=vifvm115.0, mac=00:16:3e:7a:X:X'] vnc = 0 vcpus = 6 vncviewer = 0 serial = 'pty' disk = ['phy:/dev/xen/vm115_img,xvda1,w', 'phy:/dev/xen/vm115_swap,xvda2,w'] domU kernel: 2.6.32-431.5.1.el6.x86_64 root@web2 [~]# virt-what xen root@web2 [~]# == Second domU == virt-what and cPanel scripts report domU as: xenhvm dom0: 3.10.32-11.el6.centos.alt.x86_64 Xen 4.2.4-29.el6 domU Config: bootloader = '/usr/bin/pygrub' extra = '' memory = 6144 hostname = 'web3.x.ca' cpu_weight = 256 name = 'vm116' vif = ['ip=205.X.X.X, vifname=vifvm116.0, mac=00:16:3e:cf:X:X'] vnc = 0 vcpus = 6 vncviewer = 0 serial = 'pty' disk = ['phy:/dev/xen/vm116_img,xvda1,w', 'phy:/dev/xen/vm116_swap,xvda2,w'] domU kernel: 2.6.32-431.5.1.el6.x86_64 root@web3 [~]# virt-what xen xen-hvm root@web3 [~]# Any idea why? Kinds regards, Karl

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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

1 0

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

2 1

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

2 4

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

4 7

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

2 1

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

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

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

3 7

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.

4 11

sorting virtual network interface names with xen
by lee 06 Jun '14

06 Jun '14

Hi, how would I make it so that a particular virtual network interface of dom0 is attached to a particular bridge created for a particular VM? When I start the VM with 'virsh start <domU>', I get interfaces vif1.0, vif1.1 and vif1.2. After shutting down domU with 'virsh shutdown <domU>' and starting it again as before, the virtual network interfaces are vif2.0, vif2.1 and vif2.2. I want them to keep their names so that they would be vif1.[0-2] again. In the end, I want to give them different names, like vif_domU.loc, vif_domU.dmz and vif_domU.mta, which they are supposed to keep consistently. Is it possible to hardcode the interface names in the domain description? Currently, the default script /etc/xen/scripts/vif-bridge is used to create them. And once hardcoded, how do I make it so that the corresponding interfaces in domU have appropriate names like eth_loc, eth_dmz and eth_mta? Generic interface names for all the bridges and interfaces would lead to total confusion in this case because I`d never be able to tell which bridge or interface in dom0 corresponds to what in any of the domUs. -- Knowledge is volatile and fluid. Software is power.

1 0

Open graphics connection with virt-manager problem
by jaumotte, styve 05 Jun '14

05 Jun '14

Hi, Actually, we study virtualization on CentOS with Xen, our goal is to test if the migration of Xen with SLES 11 to CentsOS. Our first tests are ok except for one problem and I don't find any solutions on the net. I hope, you can help me. The problem is that I can't connect to my vm desktop with Virt-Viewer. I follow the installation guide available for centos : http://wiki.centos.org/HowTos/Xen/Xen4QuickStart and http://wiki.centos.org/HowTos/Xen/Xen4QuickStart/Xen4Libvirt My CentOS is a fresh new install 6.5 with xen 4.2 and X11. >From Dom0, when I launch virt-manager, everything is ok. I can create a new vm and the first time I connect to the virtual graphics without any problems. But, if I close the desktop VM, I can't access anymore to the virtual desktop of the VM, it is as if the graphics is freazing.The VM is still alive. What is very strange is that I can connect directly with vnc client on 127.0.0.1 :5900 port. I try to launch virt-manager with " --debug " option, but don't find any interesting errors. I've got the same problem if I remotely launch a virt-manager and connect with xen+ssh from another centos 6.5. But, I can still connect from a virt-manger launched from a Rh7RC or even from a SLES 11.3. I think it becomes from virt-manager or libvirt which come with centos 6.5. I made update and I don't know what's wrong with my CentOS 6.5. Don't find any problems like this with Google ! Thank's for you help. Styve

2 1

qemu-kvm rebuild in Centos for oVirt in SIG Virt
by Douglas Schilling Landgraf 05 Jun '14

05 Jun '14

Hi guys, As we discussed in the last CentOS SIG Virt meeting below the steps that we do to rebuild the qemu-kvm from http://vault.centos.org to enable the rhev-features like live snapshot for CentOS. 1. Download the last qemu-kvm from http://vault.centos.org/${version}/updates/Source/SPackages/ 2. mock -D "${build_version}" -r epel-6-x86_64 --with=rhev-features --rebuild "${WORKSPACE}"/rpms/${qemu_kvm} --resultdir="${WORKSPACE}"/rpms --cleanup-after As you can see we don't bump the release at moment, please let me know your thoughts. If there is any volunteer to take owner of this package in the SIG group please let me know, otherwise I can take it. Here the jenkins URL: http://jenkins.ovirt.org/job/qemu-kvm-rhev_create-rpms_el6/ Thanks! -- Cheers Douglas

3 4

Log from today's IRC meeting (June 3rd, 2014)
by Lars Kurth 04 Jun '14

04 Jun '14

With slight re-ordering to keep related things together <kbsingh> lars_kurth: Hi [13:52] <kbsingh> Are we doing this meeting on irc ? <lars_kurth> kbsingh: yes, we are [13:59] <lars_kurth> gwd: Hi. [14:02] <lars_kurth> Alright. I didn't put an agenda together <gwd> I've got a couple of things I wanted to bring up. [14:04] <gwd> Who else is here for the meeting? <lars_kurth> Please do. I think KB has some too <jonludlam> Hello <lars_kurth> gwd: seems we have jonludlam, kbsingh gwd and me so far [14:05] <lars_kurth> Hi. Before we properly start. Any changes on actions on http://wiki.centos.org/SpecialInterestGroup/Virtualization/Status ? <lars_kurth> So: no changes then? [14:06] <gwd> We chatted at the hackathon (with Daniel Barrange there) about libvirt versions <jonludlam> That was a good session [14:07] <lars_kurth> gwd: what was the outcome/recommendation? <gwd> What we said there was that libvirt/libxl driver isn't yet stable, so there's no point doing a "choose a version and stick with it" thing until it is. <lars_kurth> gwd: that is what I was afraid of [14:08] <jonludlam> so libvirt becomes a 'tech preview' until it stabilises? <gwd> Er, I don't think "tech preview" <jonludlam> 'unstable'? <gwd> More like, "Not enterprise". :-) <jonludlam> ok <pasik> hello [14:09] <jonludlam> hi pasik <gwd> pasik: Hello <gwd> You know, like the kernel we want to be "enterprise" and only update every 2+ years. <lars_kurth> But that is only an issue for libxl, mot xm. Correct? If we are still talking Xen 4.4 that should not be an issue <gwd> I don't think we want to encourage anyone to use xend if we can possibly help it. <gwd> We need to transition people away from it. [14:10] <jonludlam> libvirt is a reasonable transition strategy though <gwd> Is there a need for "enterprise libvirt"? Is anyone using that? <pasik> Hopefully we can get thinks into better shape with xen 4.4 + later libvirt <lars_kurth> Agreed. How about the needs of KVM, oVirt, ... for libvirt <pasik> with the current xen 4.2 packages basicly only xend is usable (with libvirt) <gwd> pasik / euanh: We were just talking about how often to update the libvirt packages. <jonludlam> ovirt will take a good deal of porting to work with xen <lars_kurth> jonludlam: correct. But this SIG is not about Xen only [14:11] <jonludlam> true, but <gwd> jonludlam: given how much hypervisor detail is exposed by libvirt, how reliable would a libvirt/xend -> libvirt/libxl transition go? <jonludlam> What was said was that ovirt effectively doesn't need anything provided by what we're looking at in sig virt today [14:12] <jonludlam> gwd, I don't think it would be too bad - it already autodetects whether to use xl or xm based on what's installed, if you connect to xen:// <gwd> lars_kurth: I think if someone wants to use oVirt+KVM, they can use the core libvirt. <gwd> jonludlam: Sure, but as we found out, libvirt doesn't try very hard to hide the hypervisor details. [14:13] <jonludlam> qemu was mentioned in the meeting at the hackathon, but it's totally orthogonal to everything else in the SIG so far <jonludlam> gwd, but the difference between libxl and xend is much smaller than between qemu and xen <gwd> Sure; but it may still be a fairly major headache to get stuff to work. <lars_kurth> kbsingh: any views? I thought you were worried about scope creep in the SIG. <lars_kurth> Sorry: SIG [14:14] <gwd> And what actually works well with libvirt+xen at the moment anyway? xm/xl are better than virsh, IMHO <lars_kurth> gwd: That is probably correct. On the other hand, we don't have an interface into Cloud SIGs until we have libvirt and/or xapi <jonludlam> the xapi question was a bit clearer after the meetings. Anil and KB talked about an OCaml SIG that the virt SIG could <gwd> lars_kurth: Yes, but those are not going to be enterprisey either. :-) <lars_kurth> gwd: so what is the proposal <gwd> The proprosals are: depend on <gwd> 1) Choose a version of libvirt (1.2.3 maybe) and stick with it, backporting functionality we're missing. [14:16] <gwd> 2) Update the libvirt package when there's a new libvirt release until libxl support is mature enough <pasik> gwd: I use virt-install often to install new VMs <pasik> gwd: imho it's the easiest way to launch $distro installers in a PV domU [14:17] <gwd> #2 is easier for us, and will get us all the available libvirt/xen functionality; it's what we favored at the metting at the hackathon. <pasik> gwd: and virt-install works with xen4.2+xend+libvirt in el6 <gwd> The only downside is that enterprise customers don't like such frequent updates. <jonludlam> Daniel B said that #1 would be tricky, as they were refactoring the other bits of libvirt to make the xl plugin easier [14:18] <DV> We really try to not break libvirt upstream, ideally having the git version run for regtests on libxl would be a good idea <gwd> DV: Upstream Xen Project already does that. <DV> * DV agrees with danpb , even in RHEL we rebase to try to avoid backporting <gwd> Having a new libvirt shouldn't *interfere* with oVirt, virt-install, &c&c. [14:19] <DV> gwd: ah, good, are the result available publicly, if yes then maybe breakages should be reported on libvirt-list! <DV> err libvir-list@ <gwd> DV: Can you mail me about that separately? It's a bit off-topic for the current meeting. :-) [14:20] <DV> gwd: hum, the problem is that there is usually a few RHEL specific patches which used to be carried on libvirt builds <lars_kurth> Related to the libvirt version discussion is http://lists.centos.org/pipermail/centos-virt/2014-May/003832.html <pasik> gwd: and also virt-manager works OK with el6 xen4.2+xend+libvirt <pasik> gwd: for basic VM management operations, and new VM installs <DV> but I think we tried to reduce them as much as possible <pasik> gwd: so maybe that answers your "And what actually works well with libvirt+xen at the moment anyway?" <DV> pasik: ah, good to know ! [14:21] <gwd> Just to be clear: the question is NOT "do we need libvirt". Yes, we absolutely do. <gwd> The question is, "Do we need a super-stable libvirt, or can we just update on new releases for the time being." [14:22] <lars_kurth> Related to that is then: how long would we be on cutting edge libvirt version (by gut feel) <jonludlam> gwd, and, if we are updating to new releases often, is that with a view to converging? <pasik> gwd: well, centos6 is an enterprise stable distro, se people expect things to be (at least semi) stable. <pasik> gwd: we can of course make it clear libvirt will change more often.. [14:23] <gwd> Well let's discuss this on the list. <DV> * DV think within the SIG the rule 'things should be absolutely rock solid' could be relaxed, but only a bit [14:24] <gwd> kbsingh: Actually, that's another question: centos-devel isn't really that high traffic. Would it make sense to have the development discussions held on there? <gwd> OK, so that's going to be taken back to the list. [14:25] <lars_kurth> OK: adding an action <lars_kurth> gwd: are you OK to make a proposal? [14:26] <gwd> That's all the updates I have from the status: we're still waiting for the core CentOS team to get something set up to make contribution easier; there was some discussion of using koji, like Fedora. <gwd> lars_kurth: Yes, I'll do that. <lars_kurth> What next on the agenda? [14:29] <gwd> Did everyone see the Xen Hackathon meeting minutes? Anyone have any questions about that? <lars_kurth> See http://lists.centos.org/pipermail/centos-virt/2014-June/003865.html for meeting minutes <gwd> jonludlam: "...with a view to converging" -- you mean, to stop updating once libvirt+libxl is mature? Yes, that was my idea. [14:30] <jonludlam> yes <gwd> Cool. <jonludlam> although exactly how to define maturity is left unspecified :-) [14:31] <gwd> So I had one quick question for kbsingh -- should I merge my "git am" change into the main CentOS repo on github? Is there anything else that need to get that actually built? <lars_kurth> kbsingh: AYT? [14:32] <gwd> (Or maybe hughesjr ^) <gwd> OK, I think most of what I had really needs kb's input. :-) [14:34] <lars_kurth> gwd: maybe ping kbsingh and/or hughesjr an e-mail (or on-list) <gwd> Related to the "build images" thing -- is there a better way to make images that doesn't require libvirt? [14:35] <lars_kurth> Any other items from http://lists.centos.org/pipermail/centos-virt/2014-June/003865.html that we need to discuss? <gwd> The only tool like that I've ever used is xen-tools, which might be possible, but it would be nicer if there were something that could make images either for Xen or KVM. [14:36] <lars_kurth> It seems it may make sense to track jonludlam about Ocaml SIG and XAPI in the actions <jonludlam> lars_kurth, sure <lars_kurth> jonludlam: can you summarize that discussion briefly? <jonludlam> I'll poke anil :-) <jonludlam> Right: anil & KB discussed creating an OCaml SIG which would take the most recent version of the ocaml compiler: 4.01 [14:37] <jonludlam> RHEL 7 will have 4.00.1 (not recent enough) <jonludlam> SIG virt could then depend upon the OCaml SIG, but crucially, only the OCaml bindings from the sig virt would then depend upon the ocaml sig [14:38] <jonludlam> oxenstore doesn't need any runtime dependence on any ocaml libs <lars_kurth> OK. Makes sense. So the ball is in Anil's court <jonludlam> correct <lars_kurth> gwd, pasik: re xen-tools ... anyone knows whether there is such a thing for Xen and KVM [14:39] <gwd> lars_kurth: I don't understand the question. [14:41] <lars_kurth> gwd: was referring back to xen-tools ... what I meant is whether virt-manager provides the same functionality + more than xen-tools <gwd> lars_kurth: virt-install I think will do that, but it depends on libvirt; which seems to confuse some people. [14:44] <lars_kurth> gwd: re virt-install confusion. If we introduced something else, it is likely it will also confuse people. In any case may be better to rely on documentation [14:45] <gwd> virt-install> But I guess when we add an updated libvirt, then things should work more easily. <jonludlam> lars_kurth, btw, I had another action to send a PR with updated RPM packaging layout as an RFC <gwd> jonludlam: You should be able to d/l the tarballs manually though. <gwd> jonludlam: And I had an action to send you a how-to build the sig-virt-xen repos <jonludlam> yup! [14:42] <lars_kurth> jonludlam: OK, a new one? What is the context? <gwd> jonludlam: But it turns out the binary-download thing isn't ready yet -- KB doesn't want the world spamming his (previously) private ftp server. They're trying to come up with a new system similar to Fedora, but it's not ready yet. [14:43] <jonludlam> gwd, ok - are there many that aren't in the current Xen4CentOS SRPM repo? <gwd> (There was just someone on centos-virt complaining about how hard it was to build an image for Xen4CentOS and the poor documentation.) <jonludlam> lars_kurth, the idea was to try to get the work done by Andy Cooper & co to reorganise the layout of the binary RPMs taken up <lars_kurth> gwd: thank you. Got it [14:46] <lars_kurth> jonludlum: Added the action <lars_kurth> Looks we are running out of steam. Anything else? <gwd> No -- I think following up on the "where do oVirt and xapi go" discussion is the only other thing I had, but we need KB for that. <lars_kurth> OK. Maybe it is better to do this on the next call. It's easier then [14:49] <gwd> OK -- any other business? <lars_kurth> Alright: we are closed then [14:52] <gwd> OK, looks like we're done.

2 2

Why are bridges required?
by lee 04 Jun '14

04 Jun '14

Hi, all the descriptions of networking setups with VMs I`m seeing involve bridges. The only use I see for bridges is when I actually want to be able to send network traffic to multiple arbitrary interfaces connected to the bridge. I do neither need, nor want bridges when I want to keep the VMs separated, like when separating a VM in a DMZ from a VM in the LAN. The bridge acts like a hub. Looking at [1] makes it seem that this is undesirable --- otherwise there wouldn`t be need for a software switch to prevent network traffic on a bridge from going to all of the connected interfaces. When there`s a bridge with multiple VMs connected to it, is a software switch desirable to prevent network traffic on the bridge from going to interfaces it doesn`t need to go to? If so, isn`t it better not to use a bridge to begin with? Can`t we simply have virtual interfaces on the physical host which are the "other end" of the interfaces showing up in the VMs, without bridges? [2] seems to suggest to leave all bridges "dangling", i. e. it says you`re not supposed to connect an interface to the bridge. What`s the point of a bridge when only a single interface is connected to it? [1]: http://openvswitch.org/support/config-cookbooks/vlan-configuration-cookbook/ [2]: http://wiki.libvirt.org/page/Networking -- Knowledge is volatile and fluid. Software is power.

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virt June 2014