Re: [CentOS-virt] CentOS 6 VM image for paravirtualizaton on CentOS Xen server
On Mon, Mar 16, 2015 at 10:32 PM, Nico Kadel-Garcia wrote: > On Mon, Mar 16, 2015 at 4:02 AM, Manuel Wolfshant > wrote: > > > Quote from an actual installation: > > > > [root@xenh4 ~]# history| grep virt > > virt-install -n dhcpdns -p -r 1024 --os-type=linux --vnc -f > > /var/lib/xen/images/dhcpdns -s 2 -l > > http://192.168.50.40/mrepo/centos6-i386/disc1 -x > > "ks=ftp://192.168.50.40/linux/ks-minimalC6-xen.cfg"; > > > > [root@xenh4 ~]# uname -a > > Linux xenh4 2.6.18-400.1.1.el5xen #1 SMP Thu Dec 18 02:18:37 EST 2014 > i686 > > i686 i386 GNU/Linux > > > > > https://github.com/CentOS/Community-Kickstarts/blob/master/ks-minimalC6.cfg > > is quite close to the above mentioned ks-minimalC6-xen.cfg ( actually > both > > are descendants of the same template of mine ) > > Thanks The key, hinted at by various notes in this thread, was the > use of the "--location" to point to a network accessibleinstallation > repository. I'm afraid that the Xen wiki directions about "--location" > are a bit unclear about the need for this to be the base of a > deployment directory, one that *must* have a working subdirectory > called 'imagex/xen' with the relevant files in it. I admint, I have to > just love hardcoded, hidden requirements!!! > > I'll point out for others who may need to image systems quickly that > it's often more effective, especially in terms of speed and external > bandwidth, to use an internal mirror as you did. I'll also point out > that it can be awfully handy to keep such a mirror up-to-date and use > it your local configurations. I publish such scripts at > https://github.com/nkadel/nkadel-rsync-scripts, in case anyone else > wants them. > > I'll also mention my old habit in ks.cfg files of doing this, to hang > onto the actual ks.cfg instead of the confused and '%pre' and '%post' > stripped, anaconda reverse engineered oddness in > /root/anaconda-ks.cfg. > > %pre > cp -f /tmp/ks.cfg /mnt/sysimage/root/ks.cfg > %end > ___ > > Nico, I wrote tutorials on how to do this when I was using xen. I haven't used these tutorials in a couple of years but they worked then so they should still work now. This is for an automated CentOS 6 (x86_64). http://grantmcwilliams.com/item/538-centos-6-virtual-machine-64-bit-installation-on-xen Grant McWilliams http://grantmcwilliams.com/ Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Xapi packages in CentOS xen-c6 repo: first steps
I'd like to test them as soon as you get ANY repo up. Grant McWilliams http://grantmcwilliams.com/ Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. On Tue, Jul 2, 2013 at 11:23 AM, Dave Scott wrote: > Hi, > > Thanks Mike for bringing this up. > > On Jul 2, 2013, at 6:15 PM, "Mike McClurg" > wrote: > > > Hi list, > > > > Dave Scott has been working on a prototype of XenServer's Xapi running > > on stock CentOS 6.4 x86_64, with libvirt and ceph integration. He plans > > to demo this at the CentOS dojo in Aldershot next week. > > > > We'll be publishing the RPMs for this in a public Yum repo, and we would > > really like for these RPMs to eventually live in the xen-c6 repo. I was > > wondering what are the steps for making this happen, and also if it > > would be possible to make this happen before the dojo next Friday (12 > July). > > My RPMS are in a bit of an experimental state, and I'd really appreciate > people's feedback. It might be too soon to merge them into xen-c6 by next > week, but it would be nice if I could point people at an online copy > somewhere. Perhaps we could make a xen-c6-experimental repo or something? I > could then rsync new builds regularly and put setup instructions on the > CentOS wiki. > > Cheers, > Dave > > > > > > We can provide a public Yum repository with these SRPMS and RPMS, if > > that would help. Thanks, > > > > Mike > > ___ > > CentOS-virt mailing list > > CentOS-virt@centos.org > > http://lists.centos.org/mailman/listinfo/centos-virt > ___ > CentOS-virt mailing list > CentOS-virt@centos.org > http://lists.centos.org/mailman/listinfo/centos-virt > ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] turning off udev for eth0
On Tue, Jan 3, 2012 at 8:52 AM, James B. Byrne wrote: > > I have set up a kvm host and configured a standard clone > prototype for generating new guests. One persistent (pun > intended) annoyance when cloning is the behaviour of udev > with respect to the virtual network interface. > > The prototype is configured with just eth0 having a > dedicated IP addr. When the prototype is cloned udev > creates rules for both eth0 and eth1 in the clone. > Because eth1 does not exist in the cloned guest one has to > manually edit /etc/udev/rules.d/70-persistent-net.rules to > get rid of the bogus entries and then restart the clone > instance to have the changes take effect. All this does is > return the new guest to the prototype eth0 configuration. > > Is there no way to alter udev's behaviour? Is udev even > needed on a server system using virtual hardware? > Altering the rules file not a big deal in itself but it > adds needless busywork when setting up a new guest. > > -- > *** E-Mail is NOT a SECURE channel *** > James B. Byrnemailto:byrn...@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 > > I do this on VM clones. It depends on your OS but where I've had to do it is with Ubuntu VMs. I'm not sure where exactly they set that in CentOS but I'd start looking in /lib/udev/rules.d/75-persistent-net-generator.rules Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Should I switch and if so what is the procedure
On Fri, Oct 7, 2011 at 8:03 AM, Ed Heron wrote: > On Thu, 2011-10-06 at 01:46 +0200, Dennis Jacobfeuerborn wrote: > > ... > > The question is what does Xen offer that KVM cannot provide? Looking at > the > > slides of the KVM Forum 2011 ( > http://www.linux-kvm.org/page/KVM_Forum_2011) > > there seem to be many interesting improvements in the pipeline so at some > > point the question really is why hold on to Xen at all when there is not > > real reason to? > > ... > > For me, it isn't "why hang onto Xen?", it's "why convert my 18 > virtualization servers?" Most of my servers are remote. I have 8 > physical locations. Each location has a spare server for redundancy. > To change to anything else, I'd need a compelling reason as the time and > effort and, potentially, travel expenses would be significant. > > Looking at scheduled CentOS 5 EOL, I can get other things done before > having to tackle major upgrades. When I do start working on my next > iteration of my system design, I'll be considering all hypervisors. > > And in addition to that if it isn't broken CentOS 5.7 just came out so it's not like it's an old unsupported distribution and I bet that isn't the last update that Redhat will do. I just moved some of my VMs to XCP as a test which is using the exact same version of the Xen hypervisor that I was running before. In my opinion the Hypervisor isn't really that important anymore. What's more important is the management tools for them. With the Cloud.com acquisition by Citrix, OpenStack and more I think one would spend more time thinking of these tools than which hypervisor to use. Another point would be that the Dom0 doesn't really matter that much. It's not like you'll ever change it outside of adding security patches. By desgin the Dom0 just sits there and manages DomU's. If anything the DomU OS is more important. Grant McWilliams http://grantmcwilliams.com/ Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] (no subject)
Or ban Indonesia since that's where it's coming from. I can post a comment with anyone's email as the reply to address. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. On Wed, Jul 27, 2011 at 4:53 AM, Dmitry E. Mikhailov < d.mikhai...@infocommunications.ru> wrote: > On Wednesday 27 July 2011 14:37, Grant McWilliams wrote: > > http://nichejunky.com/google.php > ban this spammer please > ___ > CentOS-virt mailing list > CentOS-virt@centos.org > http://lists.centos.org/mailman/listinfo/centos-virt > ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
[CentOS-virt] (no subject)
http://nichejunky.com/google.php ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Xen version
On Thu, Dec 16, 2010 at 2:19 AM, wrote: > Paul Piscuc writes: > > > « HTML content follows » > > Hi, > > > > > > We are thinking of using CentOS with XEN in production, but we are facing > > some issues regarding the 3.0.3 version of the xen hypervisor and windows > > paravirtualization. The drivers we are using are from here > > (http://wiki.xensource.com/xenwiki/XenWindowsGplPv> > http://wiki.xensour > > ce.com/xenwiki/XenWindowsGplPv). The solution we found is upgrading to > xen > > 3.4.2, using a strange repository (http://gitco.de>gitco.de), and > > everything seems to work. Now the question is: would you recomand using > > the 3.0.3 kernel provided by CentOS in production and searching for other > > paravirtualization drivers, or go with 3.4.2? Is this version of the > > hypervisor stable? > > Why get complicated and not use KVM? Xen's future @ RedHat is not that > bright. > > My 2 pence. > > -- > Nux! > www.nux.ro Yes, installing Xen 3.4.2 is very complicated. It's amazing how anyone can pull it off! :-) wget http://www.gitco.de/linux/x86_64/centos/5/CentOS-GITCO.repo -O /etc/yum.repos.d/gitco.repo yum groupinstall Virtualization Or you could just put in an XCP install disk and take a nap. You'd have the very stable RHEL 5.5 base for Dom0, Xen 3.4.2 and a kernel roughly equivalent to what you get in RHEL6. For the record RHEL6 guests run on Xen as will any future Linux Distros. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] performance differences between kvm/xen
> > > > One thing that I think probably needs to be modified for our needs is a > Dom0 > > controller to run various tests in each DomU simultaneously then collate > the > > date. > > Virtual worlds are more complex than non-virtual ones. Sometimes > something > > runs great in on VM but drags when multiple VMs are being used. > > I was also going to mention that we should look at scalability and > performance isolation. > Some references and previous studies here: > > http://todddeshane.net/research/Xen_versus_KVM_20080623.pdf > http://clarkson.edu/~jnm/publications/isolation_ExpCS_FINALSUBMISSION.pdf<http://clarkson.edu/%7Ejnm/publications/isolation_ExpCS_FINALSUBMISSION.pdf> > http://clarkson.edu/~jnm/publications/freenix04-clark.pdf<http://clarkson.edu/%7Ejnm/publications/freenix04-clark.pdf> > > Also, is there anybody that has access to or would be able to get > access to run SPECvirt? > http://www.spec.org/virt_sc2010/ > > Thanks, > Todd > > > So you've already done a lot of this then Todd? Should we just be making a standardized test out of your work? Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] performance differences between kvm/xen
On Thu, Oct 21, 2010 at 12:50 PM, Grant McWilliams < grantmasterfl...@gmail.com> wrote: > > > On Thu, Oct 21, 2010 at 3:29 AM, Karanbir Singh wrote: > >> On 10/21/2010 12:01 AM, Grant McWilliams wrote: >> > So what we're on the verge of doing here is creating a test set... I'd >> > love to see a shell script that ran a bunch of tests, gathered data >> > about the system and then created an archive that would then be uploaded >> > to a website which created graphs. Dreaming maybe but it would be >> > consistent. So what goes in our testset? >> >> I am trying to create just that - a kickstart that will build a machine >> as a Xen dom0, build 4 domU's, fire up puppet inside the domU's do the >> testing and scp results into a central git repo. Then something similar >> for KVM. >> >> will get the basic framework online today. >> >> - KB >> __ >> > > Do you suppose you could get it to use Phoronix Test Suite so > we can start to have measurable stats? We could do the same thing for any > VM software - even > the ones that don't allow publishing stats in the EULA... > > I'm also wondering if we should do the whole test suite or a subset. > Here is the list of tests.. > > One thing that I think probably needs to be modified for our needs is a Dom0 controller to run various tests in each DomU simultaneously then collate the date. Virtual worlds are more complex than non-virtual ones. Sometimes something runs great in on VM but drags when multiple VMs are being used. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] performance differences between kvm/xen
On Thu, Oct 21, 2010 at 3:29 AM, Karanbir Singh wrote: > On 10/21/2010 12:01 AM, Grant McWilliams wrote: > > So what we're on the verge of doing here is creating a test set... I'd > > love to see a shell script that ran a bunch of tests, gathered data > > about the system and then created an archive that would then be uploaded > > to a website which created graphs. Dreaming maybe but it would be > > consistent. So what goes in our testset? > > I am trying to create just that - a kickstart that will build a machine > as a Xen dom0, build 4 domU's, fire up puppet inside the domU's do the > testing and scp results into a central git repo. Then something similar > for KVM. > > will get the basic framework online today. > > - KB > __ > Do you suppose you could get it to use Phoronix Test Suite so we can start to have measurable stats? We could do the same thing for any VM software - even the ones that don't allow publishing stats in the EULA... I'm also wondering if we should do the whole test suite or a subset. Here is the list of tests.. aio-stress apache battery-power-usage blogbench bork build-apache build-imagemagick build-linux-kernel build-mplayer build-mysql build-php bullet bwfirt byte c-ray cachebench compilebench compliance-acpi compliance-sensors compress-7zip compress-gzip compress-lzma compress-pbzip2 crafty dbench dcraw doom3 encode-ape encode-flac encode-mp3 encode-ogg encode-wavpack espeak et etqw-demo-iqc etqw-demo etqw ffmpeg fhourstones fio fs-mark gcrypt geekbench gluxmark gmpbench gnupg graphics-magick gtkperf hdparm-read himeno hmmer idle-power-usage idle iozone j2dbench java-scimark2 jgfxbat john-the-ripper juliagpu jxrendermark lightsmark mafft mandelbulbgpu mandelgpu mencoder minion mrbayes n-queens nero2d network-loopback nexuiz-iqc nexuiz npb openarena openssl opstone-svd opstone-svsp opstone-vsp padman pgbench phpbench postmark povray prey pybench pyopencl qgears2 quake4 ramspeed render-bench scimark2 smallpt-gpu smallpt smokin-guns specviewperf10 specviewperf9 sqlite stream stresscpu2 sudokut sunflow supertuxkart systester tachyon tiobench tremulous trislam tscp ttsiod-renderer unigine-heaven unigine-sanctuary unigine-tropics unpack-linux urbanterror ut2004-demo vdrift-fps-monitor vdrift video-cpu-usage video-extensions warsow wine-cloth wine-domino wine-fire2 wine-hdr wine-metaballs wine-vf2 wine-water x11perf x264 xplane9-iqc xplane9 yafray Grant McWilliams . ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] performance differences between kvm/xen
On Wed, Oct 20, 2010 at 6:24 AM, Tom Bishop wrote: > Ok so I'd like to help, since most folks have Intel Chipsets, I have a AMD > 4p(16 core)/32gig memory opteron server that I'm running that we can get > some numbers onbut it would be nice if we could run apples to apples...I > have iozone loaded and can run that but would be nice to run using the same > parametersis there any way we could list the types of test we would like > to run and the actual command with options listed and then we would have > some thing to compare at least level the playing field...KB, any thoughts, > is this a good idea? > > > On Wed, Oct 20, 2010 at 6:52 AM, Karanbir Singh wrote: > >> On 10/20/2010 12:35 PM, Dennis Jacobfeuerborn wrote: >> > Being skeptical is the best approach in the absence of >> > verifiable/falsifiable data. Today or tomorrow I'll get my hands on a >> new >> > host system and although it is supposed to go into production >> immediately I >> > will probably find some time to do some rudimentary benchmarking in that >> > regard to see if this is worth investigating further. Right now I'm >> >> That sounds great. I've got a machine coming online in the next few days >> as well and will do some testing on there. Its got 2 of these : >> >> Intel(R) Xeon(R) CPU E5310 >> >> So not the newest/greatest, but should be fairly representative. >> >> > planning to use fio for block device measurements but don't know any >> decent >> > (and uncomplicated) network i/o benchmarking tools. Any ideas what tools >> I >> > could use to quickly get some useful data on this from the machine? >> >> iozone and openssl speed tests are always a good thing to run as a 'warm >> up' to your app level testing. Since pgtest has been posted here >> already, I'd say that is definitely one thing to include so it creates a >> level of common-code-testing and comparison. mysql-bench is worth >> hitting as well. I have a personal interest in web app delivery, so a >> apache-bench hosted from an external machine hitting domU's / VM's ( but >> more than 1 instance, and hitting more than 1 VM / domU at the same time >> ) would be good to have as well. >> >> And yes, publish lots of machine details and also details on the code / >> platform / versions used. I will try to do the same ( but will limit my >> testing to whats already available in the distro ) >> >> thanks >> >> - KB >> __ >> > So what we're on the verge of doing here is creating a test set... I'd love to see a shell script that ran a bunch of tests, gathered data about the system and then created an archive that would then be uploaded to a website which created graphs. Dreaming maybe but it would be consistent. So what goes in our testset? Just a generic list, add to or take away form it.. - phoronix test suite ? - iozone - kernbench - dbench - bonnie++ - iperf - nbench The phoronix test suite has most tests in it in addition to many many others. Maybe a subset of those tests with the aim of testing Virtualization would be good? Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] performance differences between kvm/xen
> > If I understand that paper correctly, HVM+VT-d outperforms PV by quite a > > lot (if you have VT-d support on your system). > > > > Thanks for that link. Just to make my criticism of the initial claim more > clear: I don't claim that HVM can never be faster than PV but that you need > to understand when exactly this is the case. For example I'm not sure that > x86_64 vs. x86 really enters into this but I can definitely see VT-d making > an impact there. > > Regards, >Dennis > > > Even though this is Intel talking I'd still be very sceptical of getting those numbers since this is quite the opposite of what I've seen. Maybe the vt-d is getting good enough to actually accelerate IO operations but even so that would only happen on the latest hardware. I will say that Xen has a really long packet path though. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] performance differences between kvm/xen
On Sat, Oct 16, 2010 at 12:58 PM, Dennis Jacobfeuerborn < denni...@conversis.de> wrote: > On 10/16/2010 08:11 PM, Pasi Kärkkäinen wrote: > > On Thu, Oct 14, 2010 at 02:16:42PM +0100, Bart Swedrowski wrote: > >> Hi Karanbir, > >> > >> On 14 October 2010 19:59, Karanbir Singh wrote: > >>> > >>> On 10/14/2010 07:48 AM, Tom Bishop wrote: > >>>> I think xen is still on top in terms of performance and > featuresnow > >>> > >>> that is indeed what it 'feels' like, but I'm quite keen on putting some > >>> numbers on that. > >> > >> I have done some testing some time ago on one of the EQ machines that > >> I got from hetzner.de. Full spec of the machine was as following: > > > > Note that 64bit Xen guests should be HVM, not PV, for best performance. > > Xen HVM guests obviously still need to have PV-on-HVM drivers installed. > > > > 32bit Xen guests can be PV. > > Hm, why would HVM be faster than PV for 64 bit guests? > > Regards, >Dennis > lol, there's seems to be a lot of hearsay surrounding performance and Xen. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] which virtualization platform to choose
On Tue, Jul 27, 2010 at 10:52 PM, Luke S Crawford wrote: > Grant McWilliams writes: > > > I'm not sure any of the rest of us have ever had to recompile the kernel > to > > get xen to work either. I have 160 or so DomUs on CentOS Dom0s and still > > haven't recompiled a kernel. > > > how many guests per dom0? for my smallest plans I approach 160 DomUs per > dom0, and I /have/ had to recomplile to make that work. (though, it's been > rather a long time since I tried it with a CentOS/xen kernel rather than > a xen.org kernel.) > > What kind of situation would you be trying to run 160 DomUs per Dom0? I'd be curious about your particular needs for having that many DomUs per Dom0. Did you run into a hard coded limit on the number of DomUs you could have? Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] which virtualization platform to choose
On Tue, Jul 27, 2010 at 4:17 AM, Gilberto Nunes wrote: > Hi Eric... > > I'm using virtio drivers on my hosts... Both Xen and KVM. > > What I see is the KVM has been easier to manage and maitain. > > Also, KVM is more easier to implement, 'cause I don't need re-compile > the kernel...It's just do a modprobe and everything is well... > > Thanks > I'm not sure any of the rest of us have ever had to recompile the kernel to get xen to work either. I have 160 or so DomUs on CentOS Dom0s and still haven't recompiled a kernel. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] RHEL 5.5 Xen fixes
On Wed, Mar 31, 2010 at 11:38 AM, Pasi Kärkkäinen wrote: > Hello, > > RHEL 5.5 has been released, and it contains many Xen related fixes. > > Here's the most important of the them.. fixing a dom0 caching bug which > could cause domU disk corruption when the domU disk was accessed from dom0 > after the domU was shutdown. Most people noticed this bug when pygrub > used wrong (cached) information. > > "pygrub uses cached and eventually outdated grub.conf, kernel and initrd": > https://bugzilla.redhat.com/show_bug.cgi?id=466681 > > > And some more: > > "Xen hypervisor doesn't mask xsave feature from the guest; Fedora 11 PV > domU kernel crashes": > https://bugzilla.redhat.com/show_bug.cgi?id=524719 > > "[RHEL-5 Xen]: F-11 Xen 64-bit domU cannot be started with > 2047MB of > memory": > https://bugzilla.redhat.com/show_bug.cgi?id=502826 > > " Boot hang when installing HVM DomU": > https://bugzilla.redhat.com/show_bug.cgi?id=524052 > > "[RHEL5 Xen]: PV guest crash on poweroff": > https://bugzilla.redhat.com/show_bug.cgi?id=540811 > > "[RHEL5 Xen]: Cpu frequency scaling is broken on Intel": > https://bugzilla.redhat.com/show_bug.cgi?id=553324 > > > > RHEL 5.5 kernel changelog: > http://rhn.redhat.com/errata/RHSA-2010-0178.html > > > Work-in-progress (Not yet in 5.5): > > "Grub2 guest support for RHEL5 Xen pygrub": > https://bugzilla.redhat.com/show_bug.cgi?id=577511 > > > -- Pasi > Are these changes in the kernel or changes to the installed Xen? I'm wondering if this effects anyone using Xen 3.4 or newer. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] moving from Xen to KVM
On Wed, Mar 17, 2010 at 6:35 AM, Dennis J. wrote: > On 03/17/2010 02:15 PM, Hildebrand, Nils, 232 wrote: > > Hi, > > I have 31 DomUs up and running on a single Box - and have a strong > feeling that even 60 will run flawless. > > But: All of them are Para-Virtualized. > > > > I have no problem with disk IO-Bottlenecks since my DomUs are not > Database-Servers - so there is mostly static information in the filesystems. > > The term "paravirtualization" is becoming quite dated. Even if you install > a KVM guest without that option if you choose the virtio driver inside then > you still end up with "paravirtualized" I/O. With the advent of things like > nested page tables and SR-IOV the "fully virtualized=slow, > paravirtualized=way faster" logic is no longer necessarily true at least > not for every aspect of the system. > > Regards, > Dennis > In the Xen world paravirtualizing will be replaced by Hybrid virtualizing. As hardware virt becomes faster (ie, not so slow) then Xen will change to using HVM as the default and paravirtualize EVERYTHING else. This is not the same thing as KVM which uses hardware virt for cpu, emulation for most things except disk and network which are paravirtualized (if chosen). I look forward to this as HVM in Xen is slower than KVM even though it's kind of doing the same thing. However, I don't think people have benchmarked either enough to realize how much of a hit we're taking with virtio. KVM has some neat tricks up their sleeve as well like shared memory, nesting etc.. I may put up a KVM box just because I need nesting (for a classroom to teach virtualization). Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Silly question about KVM
On Wed, Mar 17, 2010 at 12:02 PM, Scot P. Floess wrote: > > Sure, I understand the support until 2014...was more thinking of moving to > 6 and beyond... > > People focus on this a lot but really you might have 1 machine that needs Dom0 support and 50 that need DomU support. The majority of Virtual Machines will need DomU support which will be included indefinitely. Dom0 support is already becoming a pain but either that will be fixed by a) Xen Dom0 getting into the mainline kernel b) someone create a stripped down Dom0 OS just for the hypervisor. Effectively this is what XCP is doing I think. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Introducing ConVirt 2.0
On Tue, Mar 9, 2010 at 12:28 PM, jd wrote: > Thanks for sharing your view points. > > You are right, If some one wants to make a mess.. they can do it as easily > with Web interface as with command line tools. > > > As far as *good* reasons why you may want to consider ConVirt 2.0 for your > needs, please see the following url, > > > http://convirture.com/products_opensource.html > > Feel free to compare it with other open source tools and give suggestions > on what you would like to see. > > Just a side note, one announcement per release is hardly be categorized > under "spamming" or "commercials". > > Product websites rarely answer any questions about the product because they're too general. The word commercial comes to mind in that regard because you can read the product description and still have no idea what it does and even more importantly what it doesn't do. Nobody wants to advertise what their product doesn't do. For example **New* Multi-user administration* ConVirt 2.0 Open Source enables you to share responsibility for managing the virtualized environment between multiple administrators while maintaining full accountability. Each administrator has his or her own login and all of the actions they perform are being continuously audited. This tells me that we can have more than one person administering the VMs and we know what they're doing as well. Does this also mean we can restrict said administrators so Bob can only administer VM1 and VM2 but not VM3? Who knows. Maybe this is just a sudo group that has control of the VM commands and they're being run as root. If that's the case I can do that with a one liner in sudoers so it doesn't really solve anything. I think this is the general feeling about URLs to product websites. The real information ends up being gathered in forums like this one or by going through the laborious process of trying out every singe Xen GUI interface before you finally decide to write your own. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Introducing ConVirt 2.0
On Sun, Mar 7, 2010 at 12:54 AM, Christopher G. Stach II wrote: > - "Pasi Kärkkäinen" wrote: > > > > RHEL/CentOS doesn't provide web-based management.. or even easy > > multi-host / cluster management of virtualization nodes. > > > > -- Pasi > > Are there any *good* reasons? (Since I really hate commercials, I feel > compelled to present my contrarian viewpoint.) ConVirt addresses a pretty > small portion of the virtualization landscape, and it consists of only a few > significant parts: > > 1. Do what other free and open tools already do. > 2. Slap a web interface on it! > 3. Spam lists. > 4. Rope in suckers. > > The suggestion that a web interface is a value add to an infrastructure > issue is at least insulting. You could attempt to slap a web interface on a > fuel injection system (or maybe at least give access to the magic a la > MegaSquirt), but a bunch of assholes are still going to blow something up. > It's not going to give any admin worth his or her salt a boner because it's > not readily scriptable and it amounts to candy for retards. Secondly, > everything else that it does is already there. If you can't do it, you > shouldn't be touching the machines. > > The tool may or may not address some vanilla installations (if there ever > was one), but if you need something like that, you are probably better off > with EC2 or at least letting someone else handle it. > > -- > Christopher G. Stach II > http://ldsys.net/~cgs/ <http://ldsys.net/%7Ecgs/> > As these tools become more mature I'd like to see some comparisons because I too get a little tired of all the hype surrounding 20 tools that do exactly the same thing. I played with Convirt quite a while ago but it either didn't install right or didn't work right. Version 2.0 looks better. But then we have Eucalyptus, Enomalism, Convirt, Orchestra, Xen Admin, DTC-Xen, Cloudmin and I'd guess a whole bunch more. I wrote my own for classroom purposes that reads a roster and lets me act on whole classes of machines. I didn't release it because I think we have enough Xen guis. What we need to do is combine resources and make one real GOOD one. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Thoughts on storage infrastructure for small scale HA virtual machine deployments
> > If all the 40 VMs start copying files at the same time that would mean > > that the bandwidth share for each VM would be tiny. > > Would they? It's a possibility, and fun to think about, but what are the chances? You will usually run into this with backups, cron, and other scheduled [non-business load] tasks. These are far cheaper to fix with manually adjusting schedules than any other way, unless you are rolling in dough. I have a classroom environment where every VM is always doing the same thing in step ie. formatting partitions, installing software etc.. We hit the disk like a bunch of crazy people. I'm replacing my setup with three Intel SSDs in a RAID0 with either iSCSI or ATAoE. The RAID0 will be synced to a disk based storage as backup. We'll see pretty soon how many concurrent disk based operations this setup can handle. I'll be bonding 3 or 4 of the iSCSI box ethernet cards and then going from there to see what each of the servers in the cloud needs as far as their connection. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Xen Database vms
tion: 171.0977 > per-request statistics: > min: 5.67ms > avg: 8.55ms > max:133.64ms > approx. 95 percentile: 9.84ms > > Threads fairness: > events (avg/stddev): 5000./2.55 > execution time (avg/stddev): 42.7744/0.00 > > > 2010/1/15 compdoc > > Don't use .img files for Databases! I've done the mysqlbench test on the same machine with the same database with using LVM and img files and with .img files I got within 5% of the Dom0 speed. When I moved the DomU to using LVM I got within 1% of Dom0 speed. This is the one instance where there's a definite advantage to LVM over img files. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Slightly OT: FakeRaid or Software Raid
On Thu, Dec 3, 2009 at 6:08 AM, Christopher G. Stach II wrote: > - "Grant McWilliams" wrote: > > > On Wed, Dec 2, 2009 at 9:48 PM, Christopher G. Stach II < > > c...@ldsys.net > wrote: > > > > - "Grant McWilliams" < grantmasterfl...@gmail.com > wrote: > > > > > a RAID 10 (or 0+1) will never reach the write... performance of > > > a RAID-5. > > > > (*cough* If you keep the number of disks constant or the amount of > > usable space? "Things working" tends to trump CapEx, despite the > > associated pain, so I will go with "amount of usable space.") > > > > No. > > > > -- > > Christopher G. Stach II > > > > Nice quality reading. I like theories as much as the next person but > > I'm wondering if the Toms Hardware guys are on crack or you disapprove > > of their testing methods. > > > > http://www.tomshardware.com/reviews/external-raid-storage,1922-9.html > > They used a constant number of disks to compare two different hardware > implementations, not to compare RAID 5 vs. RAID 10. They got the expected > ~50% improvement from the extra stripe segment in RAID 5 with a serial > access pattern. Unfortunately, that's neither real world use nor the typical > way you would fulfill requirements. If you read ahead to the following > pages, you have a nice comparison of random access patterns and RAID 10 > coming out ahead (with one less stripe segment and a lot less risk): > > http://www.tomshardware.com/reviews/external-raid-storage,1922-11.html > http://www.tomshardware.com/reviews/external-raid-storage,1922-12.html > > -- > Christopher G. Stach II > > So if I have 6 drives on my RAID controller which do I choose? If I have to add two more drives to the RAID 10 to equal the performance of a RAID 5 I could just make it a RAID 5 and be faster still. RAID 5 is faster than RAID 10 for reads and writes. However, you are right on the IOs. The RAID 10 pretty much trounced RAID 5 on IOs in all tests. What wasn't in the test (but is in others that they've done) is RAID 6. I'm not sure I'm sold on it because it gives us about the same level of redundancy as RAID 10 but with less performance than RAID 5. Theoretically it would get soundly trounced by RAID 10 on IOs and maybe be slower on r/w transfer as well. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Slightly OT: FakeRaid or Software Raid
On Wed, Dec 2, 2009 at 9:48 PM, Christopher G. Stach II wrote: > > - "Grant McWilliams" wrote: > > > Interesting thoughts on raid5 although I doubt many would agree. > > That's okay. We all have our off days... Here's some quality reading: > > http://blogs.sun.com/bonwick/entry/raid_z > http://www.cyberciti.biz/tips/raid5-vs-raid-10-safety-performance.html > http://www.miracleas.com/BAARF/RAID5_versus_RAID10.txt > http://www.miracleas.com/BAARF/1.Millsap2000.01.03-RAID5.pdf > http://www.codinghorror.com/blog/archives/001233.html > http://web.ivy.net/carton/rant/ml/raid-raid5writehole-0.html > > Maybe you are thinking of RAID 6. > > > I don't see how the drive type has ANYTHING to do with the RAID > > level. > > IOPS, bit error ratio, bus speed, and spindle speed tend to factor in and > are usually governed by the drive type. (The BER is very important for how > often you can expect the data elves come out and chew on your data during > RAID 5 rebuilds.) You will use those numbers to calculate the number of > stripe segments, controllers, and disks. Combine that with the controller's > local bus, number of necessary controllers, host bus, budget, and other > business requirements and you have a RAID type. > > > a RAID 10 (or 0+1) will never reach the write... performance of > > a RAID-5. > > (*cough* If you keep the number of disks constant or the amount of usable > space? "Things working" tends to trump CapEx, despite the associated pain, > so I will go with "amount of usable space.") > > No. > > -- > Christopher G. Stach II > > Nice quality reading. I like theories as much as the next person but I'm wondering if the Toms Hardware guys are on crack or you disapprove of their testing methods. http://www.tomshardware.com/reviews/external-raid-storage,1922-9.html Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Slightly OT: FakeRaid or Software Raid
On Wed, Dec 2, 2009 at 9:51 PM, Christopher G. Stach II wrote: > - "Grant McWilliams" wrote: > > > Portability is no different with a RAID controller as long as you've > > standardized on controllers. > > For this to be true, it would have to be absolute. Since many people have > evidence that it is not true, it's not absolute. Controllers of the same > revision and firmware version have had portability problems. > > -- > Christopher G. Stach II > > Like I said in our environment we have hundreds of drives moving between controllers *every month and have had zero problems with it. Not all machines use the same controller (some are 3ware 9550SX and some are 3ware 9650SE) nor do they use the same firmware version. We've been doing this for 3 years now and have never had a drive have problems. All drives are initialized, partitioned, formatted and populated with content in 3 locations around the world and then multiple sets are shipped to 75 machines in various geographical zones and used for one month. At this point we've done close to 10,000 swaps (300/month) and we've never had a controller not see a drive and recognize it without anything more than a tw_cli rescan. You can talk theoretics but I can tell you my real world experience. I cannot speak for other vendors but for 3ware this DOES work and is working so far with 100% success. I have a bunch of Areca controllers too but the drives are never moved between them so I can say how they'd act in that circumstance. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Slightly OT: FakeRaid or Software Raid
> Personally, I never touch raid5, but then, I'm on sata. I do agree > that there are benifits to hardware raid with battery backed cache if > you do use raid5 (but I think raid5 is usually a mistake, unless it's > all read only, in which case you are better off using main memory for > cache. you are trading away small write performance to get space; with > disk, space is cheap and performance is expensive, so personally, if > I'm going to trade I will trade in the other direction.) > > Interesting thoughts on raid5 although I doubt many would agree. I don't see how the drive type has ANYTHING to do with the RAID level. There are different RAID levels for different situations I guess but a RAID 10 (or 0+1) will never reach the write or read performance<http://www.tomshardware.com/reviews/external-raid-storage,1922-9.html>of a RAID-5. The disk space waste isn't too much of a problem anymore because as you say drives are getting much cheaper. Although on that subject I'll mention that enterprise drives and desktop drives are NOT the same thing. We deal in hundreds of drives and see about a 3% failure on desktop drives and only a fraction of that on enterprise drives. I will say though that in my opinion the one really important thing to consider is the price. These controllers aren't cheap and if you skimp you will pay. For sequential single reads (streaming one stream) I'd consider using a software "RAID" 0. For a mirror I'd consider Software RAID but once I get serious and go for RAID5 or RAID6 I'd only use Hardware RAID. That's my 2 cents. :-) Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Slightly OT: FakeRaid or Software Raid
On Wed, Dec 2, 2009 at 2:44 PM, Ben M. wrote: > Thanks for sharing Grant. Your point about hardware raid is well taken. > However, the discussion is about Fake-Raid vs. Software RAID1 and > controller/chipset dependence and portability. The portability of a > software RAID1 hard drive to an entirely different box is, I have > learned, much higher and less time consuming. > Portability is no different with a RAID controller as long as you've standardized on controllers. Our situation is not standard but hundreds of drives are swapped between machines throughout the month without an issue. We use RAID sets to transfer large amounts of data (TBs) between machines. All systems use 3ware 9550 or 9650 controllers though so you throw the set in and rescan an it's there. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Slightly OT: FakeRaid or Software Raid
On Wed, Dec 2, 2009 at 12:59 PM, Christopher G. Stach II wrote: > > - "Ben M." wrote: > > > MD RAID. I'd even opt for MD RAID over a lot of hardware implementations. > This writeup summarizes a bit of why: > > http://jeremy.zawodny.com/blog/archives/008696.html > > Hardware RAID's performance is obviously going to be better, but it's only > worth it if you *need* it (more than ~8 disks, parity). If you're just doing > RAID 0, 1, or 10 in a single box and you're not pushing it to its limits as > a DB server or benchmarking and going over it with a magnifying glass, you > probably won't notice a difference in performance. > > -- > Christopher G. Stach II > > He had a two drive RAID 1 drives and at least one of them failed but he didn't have any notification software set up to let him know that it had failed. And since that's the case he didn't know if both drives had failed or not. I wonder why he things software RAID would be a) more reliable b) fix itself magically without telling him. He never did say if he was able to use the second disk. I have 75 machines with 3ware controllers and on the very rare occasion that a controller fails you plug in another one and boot up. I don't use software RAID in any sort of production environment unless it's RAID 0 and I don't care about the data at all. I've also tested the speed between Hardware and Software RAID 5 and no matter how many CPUs you throw at it the hardware will win. Even in the case when a 3ware RAID controller only has one drive plugged in it will beat a single drive plugged into the motherboard if applications are requesting dissimilar data. One stream from an MD0 RAID 0 will be as fast as one stream from a Hardware RAID 0. Multiple streams of dissimilar data will be much faster on the Hardware RAID controller due to controller caching. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] XEN and RH 6
On Tue, Nov 10, 2009 at 7:13 AM, Dennis J. wrote: > On 11/10/2009 04:02 PM, Ray Van Dolson wrote: > > On Tue, Nov 10, 2009 at 06:57:08AM -0800, Grant McWilliams wrote: > >> All of it except for that! Your VM isn't just a process accessing a > >> disk. With KVM they've attacked the most commond devices - network and > >> disk and offered paravirtualized devices. This doesn't concern me as the > >> speed has proven to be good although in mysqlbench Xen still leads by > >> quite a bit. I'm concerned about everything else. With 41 interactive > >> VMs I worry about how fast the hypervisor can switch focus, the cpu > >> utilization of each etc.. > > > > What are the hardware specs you're running your 41 VM's off of just out > > of curiosity? > > I'd be interested in that info too especially the storage setup. I imagine > local storage isn't suitable for this many VMs on a single host. > > Regards, >Dennis > > Eight core Xeon, 32 GB of ram and local storage for now. The storage is the main bottleneck but as soon as my PO goes through I'll have a second machine providing storage from the RAID via iSCSI. I have other ideas but I'll be putting them in a different post. Students access their VM via NX. As you can imagine the requirements for this setup is not the same as for 40 web servers... I'm still in the process of finding ways of tweaking it to get whatever speed I can. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] XEN and RH 6
> > > > Which I guess makes describing a guest as "fully virtualized" or > "paravirtualized" rather pointless given that there now is just a degree of > how paravirtualized a guest is depending on the drivers you use. > > Regards, >Dennis > > I disagree completely. KVM or Xen HVM are fully virtualized except for two drivers. This is not the same thing as paravirtualized. People seem to think the only thing a computer does is access the disk and network device. With a PV everything is running native and the only overhead is from the Hypervisor. In a most cases using the VT bits in the CPU makes the virtualization slower in all aspects. This may not be the case in the future. The developers of VirtualBox have documented this. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] XEN and RH 6
> > > > I've been wondering about the definition of PV in the context of KVM/Xen. > In the Linux on Linux case for Xen PV practically means that in the HVM > case I have to access block devices using /dev/hda while in the PV case I > can use the faster /dev/xvda. When using KVM which apparently only supports > HVM I can still install a guest using the virtio drivers which seem to do > the same as the paravirtualized devices on Xen. > > So what is the KVM+virtio case if not paravirtualization? > > Regards, >Dennis > __ > All of it except for that! Your VM isn't just a process accessing a disk. With KVM they've attacked the most commond devices - network and disk and offered paravirtualized devices. This doesn't concern me as the speed has proven to be good although in mysqlbench Xen still leads by quite a bit. I'm concerned about everything else. With 41 interactive VMs I worry about how fast the hypervisor can switch focus, the cpu utilization of each etc.. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] XEN and RH 6
> Both Novell and Oracle having been deeply involved in Xen lately, both > are developing and supporting their own products based on Xen. > > -- Pasi > > ___ > I have no problem with a "better" solution than Xen because to be honest it's a pain sometimes but at this point virtually all enterprise VM deployments are either based on VMware ESX or Xen (Xenserver, VirtualIron, Amazon AWS, Oracle, Sun SVM, Redhat and Suse). This tide will change as KVM becomes more dominant in the VM space but I don't see that happening for a while. I'm also a bit skeptical as to how well a fully virtualized system (KVM) will run in comparison to a fully paravirtualized system (Xen PV). I have a system with 41 VMs on it and I'll be having 2 weeks of planned downtime in the near future. I'd like to see how these systems run under KVM. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] XEN and RH 6
On Tue, Nov 10, 2009 at 4:36 AM, carlopmart wrote: > Pasi Kärkkäinen wrote: > > On Tue, Nov 10, 2009 at 01:20:11PM +0100, carlopmart wrote: > >> Pasi Kärkkäinen wrote: > >>> On Tue, Nov 10, 2009 at 11:27:57AM +0100, carlopmart wrote: > >>>> Pasi Kärkkäinen wrote: > >>>> > >>>>>> Still it isn't official, but Citrix XenServer will disappears soon > ... It will be > >>>>>> integrated under Microsoft Hyper-V > >>>>>> > >>>>> Uhm.. I don't believe this. Where did you read that? > >>>>> > >>>>> Citrix XenServer was opensourced last week, or the hypervisor+tools > >>>>> part, the xencenter management interface remains closed source (but > it > >>>>> can also manage hyper-v). > >>>>> > >>>>>> IMHO, it isn't a good option to maintain domO virt servers based on > CentOS or RHEL > >>>>>> now ... It is the time to migrate to another solutions ... > >>>>>> > >>>>> RHEL5, with Xen, will be fully supported by Redhat until 2014. They > have > >>>>> clearly stated that many times. > >>>>> > >>>>> -- Pasi > >>>> Ok, I think I haven't explained well, sorry. Citrix Xenserver's > hypervisor and tools > >>>> was donated by Citrix last week, correct. But Citrix didn't release > more versions of > >>>> the product because it does not intend to develop it and apply new > features. Citrix > >>>> virtualization bussiness will be focused only on Management and > Desktop > >>>> virtualization using Hper-V as a first platform and second VMware. > >>>> > >>> Where did you read this? You write it like it's a fact - I haven't seen > >>> that anywhere.. ?? > >> This will be announced over next weeks ... > >> > > > > Again, are you speculating, or is this a fact? I think Citrix XenServer > 5.7 > > will be released soon :) > > Ok, stay and wait. But I repeat: Citrix will focused his efforts only on > Management > and Desktop virtualization, not on servers. First past it is do it: donate > xenserver > to opesource community. > > If this is true it will not only be the death of Xen but of Citrix as well. I don't see a company surviving that only makes a gui to manage someone else's VM solution. I think Microsoft is capable of making their own GUI. I do think that we should probably just give up on getting xen in the kernel for Dom0. It's clear that the kernel guys will never let this happen. Xen may very well become a distribution providing a Dom0. The DomU stuff is already in the kernel so a very light distribution that only provides networking tools, security tools and the Dom0 code would be fine for those who want to continue using Xen. I've not been convinced that KVM is quite ready to do what Xen does. I use it but not for production. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Xen to KVM migration
On Mon, Oct 12, 2009 at 10:30 AM, Dennis J. wrote: > On 10/12/2009 06:17 PM, Grant McWilliams wrote: > > > > On Mon, Oct 12, 2009 at 5:48 AM, Dennis J. > <mailto:denni...@conversis.de>> wrote: > > > > Hi, > > I'm thinking about how to go about migrating our Xen VMs to KVM. > > Migrating > > the configuraton should be easy using the virsh dumpxml/define > > commands but > > what is the best way to transfer the (logical volume based) images > > without > > too much downtime for the guest system? > > > > Can rsync operate on logical volumes? If so I could potentially use > > "dd" to > > transfer an initial copy of the image to the destination host and > > then shut > > down the guest, rsync the logical volumes which shouldn't take too > > long as > > not much data has to be transfered thanks to the initial "dd" and > > then boot > > the guest on the new machine. > > > > Is something like this possible or would you do something different? > > > > Regards, > >Dennis > > > > > > Can't you just use the LV in place with KVM? > > I may be wrong about this but isn't running KVM on top of the Xen > hypervisor a problem? Maybe this has changed but I thought in order to be > able to use KVM you first have to disable the Xen hypervisor and boot into > the regular Kernel. > > Regards, > Dennis > But once you have your XEN DomU config file converted to KVM you could in effect just reboot the Dom0 into a standard kernel and use KVM. Unless of course you're only moving one DomU to KVM then it wouldn't work. Grant McWilliams ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Xen to KVM migration
On Mon, Oct 12, 2009 at 5:48 AM, Dennis J. wrote: > Hi, > I'm thinking about how to go about migrating our Xen VMs to KVM. Migrating > the configuraton should be easy using the virsh dumpxml/define commands but > what is the best way to transfer the (logical volume based) images without > too much downtime for the guest system? > > Can rsync operate on logical volumes? If so I could potentially use "dd" to > transfer an initial copy of the image to the destination host and then shut > down the guest, rsync the logical volumes which shouldn't take too long as > not much data has to be transfered thanks to the initial "dd" and then boot > the guest on the new machine. > > Is something like this possible or would you do something different? > > Regards, > Dennis Can't you just use the LV in place with KVM? Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Resizing disks for VMs
On Mon, Sep 28, 2009 at 6:43 AM, Dennis J. wrote: > Hi, > Is there a way to make a PV xen guest aware of a size change of the host > disk? In my case I'm talking about a Centos 5.3 host using logical volumes > as storage for the guests and the guests running Centos 5.3 and LVM too. > What I'm trying to accomplish is to resize the logical volume for the guest > by adding a few gigs and then make the guest see this change without > requiring a reboot. Is this possible maybe using some kind of bus rescan in > the guest? > > Regards, > Dennis > Last time I checked this wasn't supported. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] dummy ethernet interfaces
On Fri, Jan 23, 2009 at 10:29 AM, Grant McWilliams < grantmasterfl...@gmail.com> wrote: > > On Fri, Jan 23, 2009 at 10:08 AM, Caitlyn O'Hanna < > raven...@virtualxistenz.com> wrote: > >> No takers on this issue? >> >> >> --Caitlyn >> >> ___ >> CentOS-virt mailing list >> CentOS-virt@centos.org >> http://lists.centos.org/mailman/listinfo/centos-virt >> > > Caitlyn, >Are you sure you're only getting 100Mb or is it identifying itself as > 100Mb? Actual speed and info it's applied to itself may be different. > > > Grant McWilliams > > Some people, when confronted with a problem, think "I know, I'll use > Windows." > Now they have two problems. > > I just tested my dummy0 network connection and I can scp at 40MB/sec which definitely puts it above the 100Mb/sec limit. Where does it identify itself as being 100Mbit? Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] dummy ethernet interfaces
On Fri, Jan 23, 2009 at 10:08 AM, Caitlyn O'Hanna < raven...@virtualxistenz.com> wrote: > No takers on this issue? > > > --Caitlyn > > ___ > CentOS-virt mailing list > CentOS-virt@centos.org > http://lists.centos.org/mailman/listinfo/centos-virt > Caitlyn, Are you sure you're only getting 100Mb or is it identifying itself as 100Mb? Actual speed and info it's applied to itself may be different. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] [GLPI #0000037] Zweirad Stadler | Neues Ticket - powernow error in Xen VM with new kernel
On Thu, Jan 22, 2009 at 3:55 PM, Phil Schaffner wrote: > On Thu, 2009-01-22 at 14:31 +0100, Kai Schaetzl wrote: > > Anyone else getting these "tickets" from sysad...@zweirad-stadler.de > > quoting old messages to this list directly to his mailbox? > > No. Haven't seen that particular spam technique before. > > Phil > > > ___ > CentOS-virt mailing list > CentOS-virt@centos.org > http://lists.centos.org/mailman/listinfo/centos-virt > Yes, I figured it was spam. Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] amazon web services and CentOS
On Sun, Sep 28, 2008 at 4:11 PM, Karanbir Singh <[EMAIL PROTECTED]>wrote: > hi, > > After much conversation to / from their end, they are in a situation where > they have offered me some access and credits to make the whole CentOS on AWS > happen. This is the sort of thing right up the VirtSIG alley, so am > wondering if there are people here who would like to help out at all ? > > -- > Karanbir Singh : http://www.karan.org/ : [EMAIL PROTECTED] > ___ > <http://lists.centos.org/mailman/listinfo/centos-virt> > It's just a Xen image with a few configuration changes isn't it? -- Grant McWilliams Some people, when confronted with a problem, think "I know, I'll use Windows." Now they have two problems. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] xen 3.2
On Wed, Jul 16, 2008 at 1:59 AM, Rudi Ahlers <[EMAIL PROTECTED]> wrote: > Grant McWilliams wrote: > >> >> >> On Mon, Jul 14, 2008 at 2:46 PM, Daniel de Kok <[EMAIL PROTECTED] > [EMAIL PROTECTED]>> wrote: >> >>On Mon, Jul 14, 2008 at 5:04 PM, Justin Lim <[EMAIL PROTECTED] >><mailto:[EMAIL PROTECTED]>> wrote: >>> Any ideal when 3.2 xen will be avail for centos? >> >>When the upstream distribution provides it. I am not sure if it is on >>their roadmap. Of course, you could also use Xen 3.2 from XenSource, >>but that's not supported here. >> >>Take care, >>Daniel >>___ >>CentOS-virt mailing list >>CentOS-virt@centos.org <mailto:CentOS-virt@centos.org> >>http://lists.centos.org/mailman/listinfo/centos-virt >> >> >> I was at a recent Linux convention and it seemed very likely that Xen is >> no longer Redhat's priority at all and would love to put KVM in it's place. >> The Redhat rep was very adamant about KVMs superiority over Xen and the >> amount of unnecessary work to integrate Xen into their kernels. Some day >> when KVM will actually do what Xen does (and do it reliably!) Xen may not be >> an easy option. >> >> Grant >> >> >> >> ___ >> >> > So are you saying we should start looking at using KVM instead? I've never > seen it, nor used it, so how much different is it from XEN? > > -- > > Kind Regards > Rudi Ahlers > > Check out my technical blog, http://blog.softdux.com for Linux or other > technical stuff > > > ___ > CentOS-virt mailing list > CentOS-virt@centos.org > http://lists.centos.org/mailman/listinfo/centos-virt > I personally like Xen even though it's a bit difficult sometimes. The reality is that there probably will be a "Linux Virtual Machine" and then there will be the other third party ones that you can run if you want to go through the trouble. Xen, VMWare, VBox etc.. are third party. KVM is and will be integrated into the OS and will be everywhere. The amount of work being done on it is frightening. However, I don't think KVM will ever do real paravirtualization as they only focus on CPUs with VT support built in. They do paravirtualize drivers but the rest is roughly equivalent to HVM in Xen. I don't use KVM in any production environment because it's not always stable. I don't use it in a development environment because it doesn't do everything I want. Both of these things will change in the future. Because of the way the KVM VMs are handled (as tasks) though I'm not sure if it will ever be very good at having one VM span multiple real pipelines. But then again I'm not sure how efficient Xen can accomplish this. I'm working on a white paper testing the capabilities and speed of the major VM technologies in various environments but I have several months of testing left before I will release it. I'll know more when I get more data. Grant ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] xen 3.2
On Mon, Jul 14, 2008 at 2:46 PM, Daniel de Kok <[EMAIL PROTECTED]> wrote: > On Mon, Jul 14, 2008 at 5:04 PM, Justin Lim <[EMAIL PROTECTED]> wrote: > > Any ideal when 3.2 xen will be avail for centos? > > When the upstream distribution provides it. I am not sure if it is on > their roadmap. Of course, you could also use Xen 3.2 from XenSource, > but that's not supported here. > > Take care, > Daniel > ___ > CentOS-virt mailing list > CentOS-virt@centos.org > http://lists.centos.org/mailman/listinfo/centos-virt > I was at a recent Linux convention and it seemed very likely that Xen is no longer Redhat's priority at all and would love to put KVM in it's place. The Redhat rep was very adamant about KVMs superiority over Xen and the amount of unnecessary work to integrate Xen into their kernels. Some day when KVM will actually do what Xen does (and do it reliably!) Xen may not be an easy option. Grant ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
