Re: [CentOS-virt] Now on to creation of disk images
On 11-07-18 8:26 AM, "Steve Campbell" wrote: > > > On 6/28/2011 10:50 AM, Ed Heron wrote: >> On Tue, 2011-06-28 at 09:30 -0400, Steve Campbell wrote: >>> Mr. Heron was so kind to make a suggestion that I should use disk images >>> to install VMs. Upon further thought, I kinda like the idea. So I >>> re-read the manual and google a little, and discover I still don't know >>> what should be in these disk images. >>> >>> Should I copy the contents of the CDs to a file or what? I've got a test >>> server at the moment with Centos 5.5 and xen installed as the host OS, >>> but have just downloaded the 5.6 CD ISOs along with the DVD ISO, so >>> I'll use 5.6 for my VMs. I've read about how I can create an image from >>> something that already exists. >>> >>> Again, any clarity would be appreciated. >>Just put the ISO's in /var/lib/xen/images and point at them. If you >> didn't download the discs, you can rip them using: >> >> dd if=/dev/ of=/var/lib/xen/images/ >> >>For example, if ripping the first 5.6 CD... >> >> dd if=/dev/hdc of=/var/lib/xen/images/CentOS-5.6-i386-d1.iso >> >> I generally rip a disc multiple times and then do a file compare to make >> sure I've got a reasonable chance of having an undamaged copy. >> >>Keep in mind that it isn't as easy to change discs when you are using >> images on a paravirtual machine. >> >>I still recommend setting up a local repository as a much better >> solution because it allows you to take a snapshot so multiple installs >> use the exact same versions of everything. >> >> > > I moved the iso images to a folder under /var/lib/xen/images and > selected it during an install for a new VM. I've run into a problem I've > not yet seen before. The first iso is used just fine, but the second is > "Not accessible", and nothing I can discover works. > > So, should the ISOs be moved directly to the images folder instead of a > folder below images? Does it matter whether I just copy the iso files > (actually, I used scp) or do they need to be run through dd? > If you have SELinux enabled then it could be denying access to images in a 'non-standard' folder. Try putting them directly in the images folder, or alternatively, if you don't care about SELinux, setting SELinux to Permissive or Disabled. Cheers, Kelvin ___ 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 20/10/10 7:01 PM, "Grant McWilliams" wrote: > > > 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 +1 for the Phoronix test suite. I was going to suggest it too. http://phoronix-test-suite.com/ It can publish stats to a central server which the phoronix folks maintain, and it records the details of the server on which the test was performed. Not sure if it's smart enough to detect a VM though. My experience with it has been limited so far but generally positive. This isn't my data, but I think it's a good example of how pts can be used to compare results from different tests and scenarios. http://global.phoronix-test-suite.com/?k=profile&u=justapost-29384-19429-181 61 Regards, Kelvin ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] (KVM) How can I migrate VM in a non shared storage environment?
On 24/06/10 7:17 AM, "Poh Yong Hwang" wrote: > I have a server running CentOS 5.5 with KVM capabilities. I need to migrate > all the VMs to another server with the exact same hardware specs. The problem > is it is running on individual harddisks, not shared storage. What is the best > way to migrate to minimise downtime? I've had good success using dd and nc (netcat) to copy the contents of a disk or disk image from one machine to another, and verifying the copy was successful with a md5sum or sha1sum of both the original and copied disk. Kelvin ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Controlling allocation of ethernet devices and KVM
On 26/11/09 10:16 PM, "Tait Clarridge" wrote: > On Fri, 2009-11-27 at 14:02 +1300, Steven Ellis wrote: >> Running Centos 5.4 with KVM on a Dell R610 server and I'd like to >> control which of the four ethernet interfaces are used for specific >> tasks >> >> My ideal configuration would be >> >> eth0 - Host traffic only, no virtual guests. Used for guest mirroring >> and management. >> eth1 - NAT guest traffic only, no address for local machine and in >> some environments in the same zone as eth0 >> eth2/3 - Allocated to two different bridge devices which might be in >> separate network zones. >> >> The configuration of eth2/3 is fairly simple, my issue is restricting >> any NAT traffic to a specific ethernet devices, and ideally one with >> no local IP. >> >> Any ideas? >> >> Steve >> > > So if I have this right, at the basic level you wish to have: > > - One interface for Host machine > - Multiple interfaces for guest traffic > > If your environment supports VLANs (802.1Q), might I suggest a trunk > port on eth1 split up into different bridges to have the KVM guests go > through to get on different VLANs/address spaces. > > This is what I currently do for Xen and it works great. What kind of > network setup to you have? Could you please provide some pointers on how you accomplished this? I've been attempting to set up a similar configuration without success. Thanks, Kelvin ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
