I've finally got a new machine coming that will allow me to play with virtualization. What might most of you recommend for the type of virtualization software I use. I seem to recall that xen might not be the best choice due to it's lack of development. I could be wrong, though. For the present time, all of the VMs will be Centos based.
Any opinion will be appreciated.
steve campbell
On 06/16/2011 08:07 AM, Steve Campbell wrote:
I've finally got a new machine coming that will allow me to play with virtualization.
I presume this means the cpu has virtualization extensions.
What might most of you recommend for the type of virtualization software I use. I seem to recall that xen might not be the best choice due to it's lack of development. I could be wrong, though. For the present time, all of the VMs will be Centos based.
Any opinion will be appreciated.
steve campbell
Wait for CentOS6 (scheduled to be available early next week) and use KVM.
Eric Shubert wrote on 06/16/2011 11:35 AM:
Wait for CentOS6 (scheduled to be available early next week) and use KVM.
I would not bank on that, given the continually sliding calendar. If in a hurry give SL6 a try. It's pretty easy to switch back to CentOS by changing the release packages.
Phil
On 06/19/2011 05:09 AM, Phil Schaffner wrote:
Eric Shubert wrote on 06/16/2011 11:35 AM:
Wait for CentOS6 (scheduled to be available early next week) and use KVM.
I would not bank on that, given the continually sliding calendar. If in a hurry give SL6 a try. It's pretty easy to switch back to CentOS by changing the release packages.
Phil
Good advice. I see on the QA schedule that the release had slid another week (again). :(
On Thu, 16 Jun 2011, Eric Shubert wrote:
On 06/16/2011 08:07 AM, Steve Campbell wrote:
What might most of you recommend for the type of virtualization software I use. I seem to recall that xen might not be the best choice due to it's lack of development. I could be wrong, though. For the present time, all of the VMs will be Centos based.
Wait for CentOS6 (scheduled to be available early next week) and use KVM.
I have KVM running on CentOS 5.6, and have had no issues at all. In fact, it has been excellent all round.
Steve
On Thu, Jun 16, 2011 at 11:07:14AM -0400, Steve Campbell wrote:
I've finally got a new machine coming that will allow me to play with virtualization. What might most of you recommend for the type of virtualization software I use. I seem to recall that xen might not be the best choice due to it's lack of development. I could be wrong, though. For the present time, all of the VMs will be Centos based.
Any opinion will be appreciated.
Xen is very actively developed upstream at xen.org, and also the bits needed to support Xen dom0 in Linux were recently merged to upstream kernel.org Linux kernel!
http://blog.xen.org/index.php/2011/06/14/linux-3-0-how-did-we-get-initial-do...
The problem with RHEL6/CentOS6 is that Redhat bought Qumranet (the KVM company) and decided to only ship KVM host support in RHEL6.
RHEL6/CentOS6 runs as Xen VM though, so you can use RHEL5/CentOS5 Xen host (dom0) and run EL6 VMs on it.
-- Pasi
On Thu, 23 Jun 2011, Pasi Kärkkäinen wrote:
The problem with RHEL6/CentOS6 is that Redhat bought Qumranet (the KVM company) and decided to only ship KVM host support in RHEL6.
RHEL6/CentOS6 runs as Xen VM though, so you can use RHEL5/CentOS5 Xen host (dom0) and run EL6 VMs on it.
The sources that will become CentOS 6 will run xen.org virtualization as a dom0, and KVM may be excluded
-- Russ herrold
Le 22/06/2011 23:12, R P Herrold a écrit :
On Thu, 23 Jun 2011, Pasi Kärkkäinen wrote:
The problem with RHEL6/CentOS6 is that Redhat bought Qumranet (the KVM company) and decided to only ship KVM host support in RHEL6.
RHEL6/CentOS6 runs as Xen VM though, so you can use RHEL5/CentOS5 Xen host (dom0) and run EL6 VMs on it.
The sources that will become CentOS 6 will run xen.org virtualization as a dom0, and KVM may be excluded
I am very surprised ot that affirmation. What of the binary compatibility of CentOS with RHEL ? It would be going in the opposite direction off Red Hat.
Alain
On 06/22/2011 11:12 PM, R P Herrold wrote:
On Thu, 23 Jun 2011, Pasi Kärkkäinen wrote:
The problem with RHEL6/CentOS6 is that Redhat bought Qumranet (the KVM company) and decided to only ship KVM host support in RHEL6.
RHEL6/CentOS6 runs as Xen VM though, so you can use RHEL5/CentOS5 Xen host (dom0) and run EL6 VMs on it.
The sources that will become CentOS 6 will run xen.org virtualization as a dom0, and KVM may be excluded
That makes not sense at all. Are you suggesting that Centos 6 will break compatibility with RHEL 6 completely?
Regards, Dennis
On Wed, Jun 22, 2011 at 05:12:27PM -0400, R P Herrold wrote:
The sources that will become CentOS 6 will run xen.org virtualization as a dom0, and KVM may be excluded
You said what?
Could one of the CentOS devs please confirm that you are going to be breaking the binary/feature compatibility with RHEL that is one of the most important facets of the CentOS project?
Thanks
On Thu, 23 Jun 2011, Neil Thompson wrote:
On Wed, Jun 22, 2011 at 05:12:27PM -0400, R P Herrold wrote:
The sources that will become CentOS 6 will run xen.org virtualization as a dom0, and KVM may be excluded
You said what?
Could one of the CentOS devs please confirm that you are going to be breaking the binary/feature compatibility with RHEL that is one of the most important facets of the CentOS project?
I did not say the CentOS project was ** going to ship ** xen; I said: "The sources that will become CentOS 6 ** will run ** xen.org virtualization as a dom0, and KVM ** may be ** excluded"
CentOS proper at the 6 level will ship KVM as that tracks the upstream, warts and all
-- Russ herrold herrold@centos.org
Le 23/06/2011 17:16, R P Herrold a écrit :
I did not say the CentOS project was ** going to ship ** xen; I said: "The sources that will become CentOS 6 ** will run ** xen.org virtualization as a dom0, and KVM ** may be ** excluded"
CentOS proper at the 6 level will ship KVM as that tracks the upstream, warts and all
I must say that the meaning of your message is not clear for me. What is the difference for you between "The sources that will become CentOS 6", and "CentOS proper" ? What do you have in mind ? Why "KVM may be excluded" ?
Regards, Alain
On 06/23/2011 06:28 PM, Alain Péan wrote:
Le 23/06/2011 17:16, R P Herrold a écrit :
I did not say the CentOS project was ** going to ship ** xen; I said: "The sources that will become CentOS 6 ** will run ** xen.org virtualization as a dom0, and KVM ** may be ** excluded"
CentOS proper at the 6 level will ship KVM as that tracks the upstream, warts and all
I must say that the meaning of your message is not clear for me. What is the difference for you between "The sources that will become CentOS 6", and "CentOS proper" ? What do you have in mind ? Why "KVM may be excluded" ?
Without implying that I can read his mind, I guess he meant "People with enough skills will be able to tweak C6 to use xen as Dom0"
On Thu, 23 Jun 2011, Manuel Wolfshant wrote:
Without implying that I can read his mind, I guess he meant "People with enough skills will be able to tweak C6 to use xen as Dom0"
Wolfie beat me to the post by eight seconds, it seems
Yes, it appears that he can read my mind
-- Russ herrold
On Thu, 23 Jun 2011, Alain Péan wrote:
I must say that the meaning of your message is not clear for me. What is the difference for you between "The sources that will become CentOS 6", and "CentOS proper" ? What do you have in mind ? Why "KVM may be excluded" ?
for reasons out of scope here, CentOS 6 has not formally issued. Thus I must speak of the 'sources that will become' CentOS 6, as there is no binary CentOS 6 yet
That said, I have been running private rebuilds of '[t]he sources that will become CentOS 6' at a virtual and colo hosting facility for which I admin, http://www.pmman.com/
As part of that work (related to KVM hardware minimum requirements, compatability with certain local libvirt based tools, and performance of KVM vs. xen), I and other techs have set up and run 'xen.org virtualization' to power the backend dom0's
As such, we have working installations that demonstrate that a person may CHOOSE to fork from CentOS's prospective KVM virtualization providing mechanism (that is, may choose to NOT use KVM), and rather one might instead use xen.org based tools
Yes ... I agree, English can be a unruly language to parse certain conditional constructs
-- Russ herrold
Russ if you have time can you elaborate more about why you are continuing to go down the Xen path, I for one would love to hear the why's and what for. I can understand the hardware requirements, and I know xen is generally going to be faster but my small requirements have decided to start moving things to KVM since that is the direction of the upstream...would welcome your opinions if you have time available...Thanks in advance :)
On Thu, Jun 23, 2011 at 10:49 AM, R P Herrold herrold@owlriver.com wrote:
On Thu, 23 Jun 2011, Alain Péan wrote:
I must say that the meaning of your message is not clear for me. What is the difference for you between "The sources that will become CentOS 6", and "CentOS proper" ? What do you have in mind ? Why "KVM may be
excluded" ?
for reasons out of scope here, CentOS 6 has not formally issued. Thus I must speak of the 'sources that will become' CentOS 6, as there is no binary CentOS 6 yet
That said, I have been running private rebuilds of '[t]he sources that will become CentOS 6' at a virtual and colo hosting facility for which I admin, http://www.pmman.com/
As part of that work (related to KVM hardware minimum requirements, compatability with certain local libvirt based tools, and performance of KVM vs. xen), I and other techs have ..snip...
-- Russ herrold _______________________________________________ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
On 06/23/2011 06:54 PM, Tom Bishop wrote:
Russ if you have time can you elaborate more about why you are continuing to go down the Xen path, I for one would love to hear the why's and what for. I can understand the hardware requirements, and I know xen is generally going to be faster but my small requirements have decided to start moving things to KVM since that is the direction of the upstream...would welcome your opinions if you have time available...Thanks in advance :)
I'll give you my reasons : - existing infra, setup and knowledge - RH gave up promoting xen because it was acquired by a competitor, not because it was not good ( or worse ) than kvm
Le 23/06/2011 18:04, Manuel Wolfshant a écrit :
I'll give you my reasons :
- existing infra, setup and knowledge
- RH gave up promoting xen because it was acquired by a competitor, not
because it was not good ( or worse ) than kvm
I think there was another very good reason why Red Hat chose KVM instead of Xen : the fact that Xen was not included in mainstream kernel. It was painful to maintain a patched kernel for it.
KVM is included in mainstream kernel since 2.6.20.
I personnally chose KVM as virtualization solution because I know it is in fact available in every Linux distribution. So if one fails, you can choose another, free, solution. But with 3.0 kernel, it will perhaps also become true for Xen...
Alain
On Thu, 23 Jun 2011, Tom Bishop wrote:
Russ if you have time can you elaborate more about why you are continuing to go down the Xen path, I for one would love to hear the why's and what for. I can understand the hardware requirements, and I know xen is generally going to be faster but my small requirements have decided to start moving things to KVM since that is the direction of the upstream...would welcome your opinions if you have time available...Thanks in advance :)
I wasn't hiding my reasoning -- part of my reasoning is soft and 'touchy, feely' but you asked ... ;)
As part of that work (related to KVM hardware minimum requirements, compatability with certain local libvirt based tools, and performance of KVM vs. xen), I and other techs have
1. support for an existing hardware delivery base -- I find that the upstream is falsely assuming everything fielded has (or should) hardware virt bits enabled. This does not match the refresh lifecycles I observe at _my_ customers, nor at our shop
2. we have a substantial investment in libvirt tools which are unproven and unqualified as to KVM until we get our hands on the official 'as issued' CentOS 6.
I've been VERY frustrated with the update API compatability in the upstream's 5 product line in this regard, as gratutitous changes, not documented, creep in, and remain unresolved for months, if not full point update cycles. I'm not a 'big enough fish' for those customers running the 'supported' product to get updates released, and so we are very conservative in what we deploy
# 649438 still NEW, opened 2010-11-03, confirmed in 5.6 on 2011-05-26 # 506688 closed unfixed 2010-11-03, opened 2009-06-18
3. performance of KVM vs. xen -- formal metrics will be issued by me once CentOS 6 issues, but in identical hardware side by side tests, xen zips, and kvm waddles
Upstream has its investment in the KVM technology to justify, and it may well be that things 'get better', but if one is not pulling metrics against the competition, one is deluding onself; I do not see evidence that this is occurring
I put numbers on out production bottlenecks; we use agile techniques to address the 'hottest' issues daily, tdd to prevent unspecified behaviours from creeping in, and 'belt and suspender' techniques to design out recurrence errors in our processes. KVM is 'not there yet' for me
-- Russ herrold
Thank You Russ and Manuel Wolfshant, I don't know you well enough to call you wolfy ;), for your comments, greatly appreciated. I support my home stuff and a small install at my church. Since Redhats' decision to go KVM and since my install will be Centos I was/have been migrating over to it...I actually cut my teeth on Xen and felt that it was more mature but for my small needs KVM had gotten close enough for my meager needs to start using it...
On Thu, Jun 23, 2011 at 11:19 AM, R P Herrold herrold@owlriver.com wrote:
On Thu, 23 Jun 2011, Tom Bishop wrote:
Russ if you have time can you elaborate more about why you are continuing
to
go down the Xen path, I for one would love to hear the why's and what
for.
I can understand the hardware requirements, and I know xen is generally going to be faster but my small requirements have decided to start moving things to KVM since that is the direction of the upstream...would welcome your opinions if you have time available...Thanks in advance :)
I wasn't hiding my reasoning -- part of my reasoning is soft and 'touchy, feely' but you asked ... ;)
..Snip...
Le 23/06/2011 17:49, R P Herrold a écrit :
On Thu, 23 Jun 2011, Alain Péan wrote:
I must say that the meaning of your message is not clear for me. What is the difference for you between "The sources that will become CentOS 6", and "CentOS proper" ? What do you have in mind ? Why "KVM may be excluded" ?
for reasons out of scope here, CentOS 6 has not formally issued. Thus I must speak of the 'sources that will become' CentOS 6, as there is no binary CentOS 6 yet
That said, I have been running private rebuilds of '[t]he sources that will become CentOS 6' at a virtual and colo hosting facility for which I admin, http://www.pmman.com/
As part of that work (related to KVM hardware minimum requirements, compatability with certain local libvirt based tools, and performance of KVM vs. xen), I and other techs have set up and run 'xen.org virtualization' to power the backend dom0's
As such, we have working installations that demonstrate that a person may CHOOSE to fork from CentOS's prospective KVM virtualization providing mechanism (that is, may choose to NOT use KVM), and rather one might instead use xen.org based tools
Yes ... I agree, English can be a unruly language to parse certain conditional constructs
Hi Russ,
Thanks for your explanations. I agree that a personal rebuild of CentOS source may choose a Xen kernel instead of upstream kernel, and tools associated with this.
I must add that, due to the fact Dom0 has been included in recent Kernel 3.0 tree, it will certainly be possible in future releases of RHEL, then CentOS, to choose either Xen or KVM as virtualization solution.
Alain
On Thu, 23 Jun 2011, Alain Péan wrote:
I must add that, due to the fact Dom0 has been included in recent Kernel 3.0 tree, it will certainly be possible in future releases of RHEL, then CentOS, to choose either Xen or KVM as virtualization solution.
perhaps, but this is in part a LKML political question, is it not?
also, upstream's 7 is some time away ... Q4 2012 is the current roadmap for 'RHEL NEXT' [1] from a recent public presentation they made
-- Russ herrold
[1] http://www.pmman.com/Red_Hat_IBM_s390_ISV_call_May-2011.pdf (PDF, 3.6M) at page 5
On Thu, Jun 23, 2011 at 11:16:47AM -0400, R P Herrold wrote:
I did not say the CentOS project was ** going to ship ** xen; I said: "The sources that will become CentOS 6 ** will run ** xen.org virtualization as a dom0, and KVM ** may be ** excluded"
CentOS proper at the 6 level will ship KVM as that tracks the upstream, warts and all
I have been looking at:
http://xen.1045712.n5.nabble.com/RHEL6-xen-and-dom0-kernel-to-test-td4413579...
which sounds like a /very/ interesting package for CentOS plus.
-
Alain Péan -
Dennis Jacobfeuerborn -
Eric Shubert -
lsc＠prgmr.com -
Manuel Wolfshant -
Neil Thompson -
Pasi Kärkkäinen -
Phil Schaffner -
R P Herrold -
R P Herrold -
Steve Campbell -
Steve Thompson -
Tom Bishop