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Posted to user@vcl.apache.org by "Waldron, Michael H" <mw...@email.unc.edu> on 2013/07/08 21:31:18 UTC
VMware vs. KVM on VCL
I'm curious to hear about people's experiences/opinions with VMware and KVM on VCL. Up to this point, we have been using the free version of VMware ESXi, but I've done some testing with KVM, and it seems to work well also.
It looks like the two will co-exist well, as KVM successfully converts the vmdk images to qcow2 format on the fly, and will even convert new images created on KVM back to vmdk format if the repository is defined as vmdk format.
So I'm toying with the idea of migrating away from VMware and going to KVM, and wanted to hear about others experiences if they've done the same, or can compare performance between the two hypervisors. Also, if you are using KVM, what OS are you running it on. The testing I did was with KVM running on Fedora 16.
Thanks,
Mike
Mike Waldron
Systems Specialist
ITS - Research Computing Center
University of North Carolina at Chapel Hill
Re: VMware vs. KVM on VCL
Posted by Curtis <se...@gmail.com>.
Hi Mike,
We run VCL on top of OpenStack on top of Ubuntu 12.04 and KVM. We did
recently migrate away from ESXi to the OpenStack cluster. Our VCL
system currently only uses Windows 7 images with virtio drivers. We
have not had any virtualization issues (that I know of).
I can't comment on performance differences, but I much prefer KVM,
though am biased towards Unix/Linux. :)
Thanks,
Curtis.
On Mon, Jul 8, 2013 at 1:31 PM, Waldron, Michael H
<mw...@email.unc.edu> wrote:
> I'm curious to hear about people's experiences/opinions with VMware and KVM
> on VCL. Up to this point, we have been using the free version of VMware
> ESXi, but I've done some testing with KVM, and it seems to work well also.
>
> It looks like the two will co-exist well, as KVM successfully converts the
> vmdk images to qcow2 format on the fly, and will even convert new images
> created on KVM back to vmdk format if the repository is defined as vmdk
> format.
>
> So I'm toying with the idea of migrating away from VMware and going to KVM,
> and wanted to hear about others experiences if they've done the same, or can
> compare performance between the two hypervisors. Also, if you are using KVM,
> what OS are you running it on. The testing I did was with KVM running on
> Fedora 16.
>
> Thanks,
> Mike
>
>
> Mike Waldron
> Systems Specialist
> ITS - Research Computing Center
> University of North Carolina at Chapel Hill
>
--
Twitter: @serverascode
Blog: serverascode.com
Re: VMware vs. KVM on VCL
Posted by Dmitri Chebotarov <dc...@gmu.edu>.
Mike
After some testing I ended up adding a column in vcl.image table to indicate if image has virtio drivers installed.
Then I changed libvirt.pm module to conditionally use virtio drivers for images with virtio drivers installed.
Thanks.
On Jul 19, 2013, at 10:34 , "Waldron, Michael H" <mw...@email.unc.edu>
wrote:
> Thanks for the responses on this, I really appreciate it.
>
> For those that mentioned they actually installed the virtio drivers in their images for best performance, did you also modify the libvirt.pm module to define the VM's setting virtio for the disk and network interface types? I noticed that it's hard-coded to always specify IDE as the disk type and a default setting on NIC type, rather than specifying virtio. I would assume these should be set to virtio for the drivers to actually be used.
>
> Mike
>
> Mike Waldron
> Systems Specialist
> ITS - Research Computing Center
> University of North Carolina at Chapel Hill
>
> From: Waldron, Michael H
> Sent: Monday, July 08, 2013 3:31 PM
> To: user@vcl.apache.org
> Subject: VMware vs. KVM on VCL
>
> I'm curious to hear about people's experiences/opinions with VMware and KVM on VCL. Up to this point, we have been using the free version of VMware ESXi, but I've done some testing with KVM, and it seems to work well also.
>
> It looks like the two will co-exist well, as KVM successfully converts the vmdk images to qcow2 format on the fly, and will even convert new images created on KVM back to vmdk format if the repository is defined as vmdk format.
>
> So I'm toying with the idea of migrating away from VMware and going to KVM, and wanted to hear about others experiences if they've done the same, or can compare performance between the two hypervisors. Also, if you are using KVM, what OS are you running it on. The testing I did was with KVM running on Fedora 16.
>
> Thanks,
> Mike
>
>
> Mike Waldron
> Systems Specialist
> ITS - Research Computing Center
> University of North Carolina at Chapel Hill
--
Thank you,
Dmitri Chebotarov
VCL Sys Eng, Engineering & Architectural Support, TSD - Ent Servers & Messaging
223 Aquia Building, Ffx, MSN: 1B5
Phone: (703) 993-6175 | Fax: (703) 993-3404
Re: VMware vs. KVM on VCL
Posted by Peter Dimitrios <pe...@gmail.com>.
We haven't made the change here, so we're running with the virtio
drivers (in Win7 and CentOS64) with <target dev='vda' bus='ide' />.
I switched a few VMs over manually to <target dev='vda' bus='virtio'
/> (directions are at
https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization_Host_Configuration_and_Guest_Installation_Guide/form-Virtualization_Host_Configuration_and_Guest_Installation_Guide-Para_virtualized_drivers-Using_KVM_para_virtualized_drivers_for_existing_devices.html
) and things seem to work the same.
We'll need to perform some stress-tests to see if the bus='virtio'
attribute makes a difference, or if qemu is being smart and adapting
to the presence of the driver because of the dev='vda' attribute).
Regards,
Peter
On Fri, Jul 19, 2013 at 10:34 AM, Waldron, Michael H
<mw...@email.unc.edu> wrote:
> Thanks for the responses on this, I really appreciate it.
>
> For those that mentioned they actually installed the virtio drivers in their
> images for best performance, did you also modify the libvirt.pm module to
> define the VM's setting virtio for the disk and network interface types? I
> noticed that it's hard-coded to always specify IDE as the disk type and a
> default setting on NIC type, rather than specifying virtio. I would assume
> these should be set to virtio for the drivers to actually be used.
>
>
> Mike
>
> Mike Waldron
> Systems Specialist
> ITS - Research Computing Center
> University of North Carolina at Chapel Hill
>
> ________________________________
> From: Waldron, Michael H
>
> Sent: Monday, July 08, 2013 3:31 PM
> To: user@vcl.apache.org
> Subject: VMware vs. KVM on VCL
>
> I'm curious to hear about people's experiences/opinions with VMware and KVM
> on VCL. Up to this point, we have been using the free version of VMware
> ESXi, but I've done some testing with KVM, and it seems to work well also.
>
> It looks like the two will co-exist well, as KVM successfully converts the
> vmdk images to qcow2 format on the fly, and will even convert new images
> created on KVM back to vmdk format if the repository is defined as vmdk
> format.
>
> So I'm toying with the idea of migrating away from VMware and going to KVM,
> and wanted to hear about others experiences if they've done the same, or can
> compare performance between the two hypervisors. Also, if you are using KVM,
> what OS are you running it on. The testing I did was with KVM running on
> Fedora 16.
>
> Thanks,
> Mike
>
>
> Mike Waldron
> Systems Specialist
> ITS - Research Computing Center
> University of North Carolina at Chapel Hill
>
RE: VMware vs. KVM on VCL
Posted by "Waldron, Michael H" <mw...@email.unc.edu>.
Thanks for the responses on this, I really appreciate it.
For those that mentioned they actually installed the virtio drivers in their images for best performance, did you also modify the libvirt.pm module to define the VM's setting virtio for the disk and network interface types? I noticed that it's hard-coded to always specify IDE as the disk type and a default setting on NIC type, rather than specifying virtio. I would assume these should be set to virtio for the drivers to actually be used.
Mike
Mike Waldron
Systems Specialist
ITS - Research Computing Center
University of North Carolina at Chapel Hill
________________________________
From: Waldron, Michael H
Sent: Monday, July 08, 2013 3:31 PM
To: user@vcl.apache.org
Subject: VMware vs. KVM on VCL
I'm curious to hear about people's experiences/opinions with VMware and KVM on VCL. Up to this point, we have been using the free version of VMware ESXi, but I've done some testing with KVM, and it seems to work well also.
It looks like the two will co-exist well, as KVM successfully converts the vmdk images to qcow2 format on the fly, and will even convert new images created on KVM back to vmdk format if the repository is defined as vmdk format.
So I'm toying with the idea of migrating away from VMware and going to KVM, and wanted to hear about others experiences if they've done the same, or can compare performance between the two hypervisors. Also, if you are using KVM, what OS are you running it on. The testing I did was with KVM running on Fedora 16.
Thanks,
Mike
Mike Waldron
Systems Specialist
ITS - Research Computing Center
University of North Carolina at Chapel Hill
Re: VMware vs. KVM on VCL
Posted by Peter Dimitrios <pe...@gmail.com>.
We've been having a really good experience using KVM / Libvirt on
Scientific Linux, using QCOW2 format and virtio drivers for both Linux
and Windows images. Once you get your base images registered in VCL,
it is pretty straightforward to manage things in the normal VCL ways.
When we need to poke around at the hypervisor level, using the
virsh CLI via ssh works well, although you can also remotely run
virt-manager to use a GUI ( virt-manager qemu+ssh://vmhost/system ).
Simple bash scripts using virsh comands via ssh are very useful to
automate housekeeping for a cluster of hypervisors, so it pays off to
become familiar with virsh.
Peter Dimitrios
Re: VMware vs. KVM on VCL
Posted by Dmitri Chebotarov <dc...@gmu.edu>.
Hi
The issue probably worth mentioning is how to access running VMs /w KVM.
If administrator is using a Linux workstation then virt-manager works fine, but it's less convenient from Windows or MacOS.
While X-Window can be installed on both OSs I find it difficult to use virt-manager on Mac OS b/c of keyboard mapping.
So far the best way that works for me is to either use local VM with Fedora & virt-manager or run vncviwer from KVM-host with X-forwarding and connect to quest VMs.
I've tried https://www.webvirtmgr.net, which seems like a good solution, but so far I'm unsuccessful to get it fully working - the products is being actively developed.
Somewhat different approach is to use a private cloud solution (in my case it's OpenNebula with .pm module) to run VCL VMs.
This allows you to use web-interface to access and manage running VMs, somewhat similar to vSphere client.
Thanks.
On Jul 9, 2013, at 13:25 , James A.s. Trimbee <tr...@cmu.edu> wrote:
> I’ve been using KVM with Rhel 6.4 and VCL in a test environment and it has been completely reliable, as in no crashes or performance degradation thus far. However, it has not been heavily loaded yet. On a purely subjective note I’ve been impressed with it – it seems very smooth. I haven’t tried much in the way of image conversion. I did find getting to grips with virt-install/virt-manager/virsh/qemu etc rather confusing at first but it becomes much clearer with use.
>
> VCL has had no issues with a lot of configuration changes on the Host (I’ve completely changed the VM working directory a couple of times), as long as the ‘VM Host Profiles’ information is correct it copes with it just fine.
>
> From: Dmitri Chebotarov [mailto:dchebota@gmu.edu]
> Sent: Monday, July 08, 2013 4:15 PM
> To: user@vcl.apache.org
> Subject: RE: VMware vs. KVM on VCL
>
> Hi Mike
>
> I've been using VMWARE and KVM in the same VCL environment for little over a month.
>
> While VCL can convert from VMDK to QCOW2 I choose to have dedicated KVM images in qcow2 format. The main reason for it is to have virtio drivers installed in VM for better OS performance. Also I couldn't get the KVM->VMWARE conversion to work - qemu-img creates image which ESXi doesn't recognize.
>
> I'm using RedHat 6.3/4 as KVM host OS. Also tried CentOS 6.3/4 before. This could be related to hardware I have (IBM HS22 blades), but RedHat runs better in my case. I've experienced unexpected reboots with CentOS. I haven't tried Fedora in production.
>
> KVM works very well so far. Looks like it creates/loads VMs faster on the same hardware/storage compared to ESXi 4.1. I haven't had any KVM related issues with VCL.
>
> I hope it helps.
>
> Thanks.
>
> From: Waldron, Michael H [mwaldron@email.unc.edu]
> Sent: Monday, July 08, 2013 3:31 PM
> To: user@vcl.apache.org
> Subject: VMware vs. KVM on VCL
>
> I'm curious to hear about people's experiences/opinions with VMware and KVM on VCL. Up to this point, we have been using the free version of VMware ESXi, but I've done some testing with KVM, and it seems to work well also.
>
> It looks like the two will co-exist well, as KVM successfully converts the vmdk images to qcow2 format on the fly, and will even convert new images created on KVM back to vmdk format if the repository is defined as vmdk format.
>
> So I'm toying with the idea of migrating away from VMware and going to KVM, and wanted to hear about others experiences if they've done the same, or can compare performance between the two hypervisors. Also, if you are using KVM, what OS are you running it on. The testing I did was with KVM running on Fedora 16.
>
> Thanks,
> Mike
>
>
> Mike Waldron
> Systems Specialist
> ITS - Research Computing Center
> University of North Carolina at Chapel Hill
>
--
Thank you,
Dmitri Chebotarov
VCL Sys Eng, Engineering & Architectural Support, TSD - Ent Servers & Messaging
223 Aquia Building, Ffx, MSN: 1B5
Phone: (703) 993-6175 | Fax: (703) 993-3404
RE: VMware vs. KVM on VCL
Posted by "James A.s. Trimbee" <tr...@cmu.edu>.
I've been using KVM with Rhel 6.4 and VCL in a test environment and it has been completely reliable, as in no crashes or performance degradation thus far. However, it has not been heavily loaded yet. On a purely subjective note I've been impressed with it - it seems very smooth. I haven't tried much in the way of image conversion. I did find getting to grips with virt-install/virt-manager/virsh/qemu etc rather confusing at first but it becomes much clearer with use.
VCL has had no issues with a lot of configuration changes on the Host (I've completely changed the VM working directory a couple of times), as long as the 'VM Host Profiles' information is correct it copes with it just fine.
From: Dmitri Chebotarov [mailto:dchebota@gmu.edu]
Sent: Monday, July 08, 2013 4:15 PM
To: user@vcl.apache.org
Subject: RE: VMware vs. KVM on VCL
Hi Mike
I've been using VMWARE and KVM in the same VCL environment for little over a month.
While VCL can convert from VMDK to QCOW2 I choose to have dedicated KVM images in qcow2 format. The main reason for it is to have virtio drivers installed in VM for better OS performance. Also I couldn't get the KVM->VMWARE conversion to work - qemu-img creates image which ESXi doesn't recognize.
I'm using RedHat 6.3/4 as KVM host OS. Also tried CentOS 6.3/4 before. This could be related to hardware I have (IBM HS22 blades), but RedHat runs better in my case. I've experienced unexpected reboots with CentOS. I haven't tried Fedora in production.
KVM works very well so far. Looks like it creates/loads VMs faster on the same hardware/storage compared to ESXi 4.1. I haven't had any KVM related issues with VCL.
I hope it helps.
Thanks.
________________________________
From: Waldron, Michael H [mwaldron@email.unc.edu]
Sent: Monday, July 08, 2013 3:31 PM
To: user@vcl.apache.org<ma...@vcl.apache.org>
Subject: VMware vs. KVM on VCL
I'm curious to hear about people's experiences/opinions with VMware and KVM on VCL. Up to this point, we have been using the free version of VMware ESXi, but I've done some testing with KVM, and it seems to work well also.
It looks like the two will co-exist well, as KVM successfully converts the vmdk images to qcow2 format on the fly, and will even convert new images created on KVM back to vmdk format if the repository is defined as vmdk format.
So I'm toying with the idea of migrating away from VMware and going to KVM, and wanted to hear about others experiences if they've done the same, or can compare performance between the two hypervisors. Also, if you are using KVM, what OS are you running it on. The testing I did was with KVM running on Fedora 16.
Thanks,
Mike
Mike Waldron
Systems Specialist
ITS - Research Computing Center
University of North Carolina at Chapel Hill
RE: VMware vs. KVM on VCL
Posted by Dmitri Chebotarov <dc...@gmu.edu>.
Hi Mike
I've been using VMWARE and KVM in the same VCL environment for little over a month.
While VCL can convert from VMDK to QCOW2 I choose to have dedicated KVM images in qcow2 format. The main reason for it is to have virtio drivers installed in VM for better OS performance. Also I couldn't get the KVM->VMWARE conversion to work - qemu-img creates image which ESXi doesn't recognize.
I'm using RedHat 6.3/4 as KVM host OS. Also tried CentOS 6.3/4 before. This could be related to hardware I have (IBM HS22 blades), but RedHat runs better in my case. I've experienced unexpected reboots with CentOS. I haven't tried Fedora in production.
KVM works very well so far. Looks like it creates/loads VMs faster on the same hardware/storage compared to ESXi 4.1. I haven't had any KVM related issues with VCL.
I hope it helps.
Thanks.
________________________________
From: Waldron, Michael H [mwaldron@email.unc.edu]
Sent: Monday, July 08, 2013 3:31 PM
To: user@vcl.apache.org
Subject: VMware vs. KVM on VCL
I'm curious to hear about people's experiences/opinions with VMware and KVM on VCL. Up to this point, we have been using the free version of VMware ESXi, but I've done some testing with KVM, and it seems to work well also.
It looks like the two will co-exist well, as KVM successfully converts the vmdk images to qcow2 format on the fly, and will even convert new images created on KVM back to vmdk format if the repository is defined as vmdk format.
So I'm toying with the idea of migrating away from VMware and going to KVM, and wanted to hear about others experiences if they've done the same, or can compare performance between the two hypervisors. Also, if you are using KVM, what OS are you running it on. The testing I did was with KVM running on Fedora 16.
Thanks,
Mike
Mike Waldron
Systems Specialist
ITS - Research Computing Center
University of North Carolina at Chapel Hill