I need to restructure my server farm from tower PC:s to a minimal amount of 1U rack servers. I am going to rely on xen virtualization, as KVM seems not to be very mature yet.
My current problem is the mail server, which uses a lot of CPU and I/O. A dedicated machine would be the best option. But would there be any sense in this:
- run the mail server in xen dom0 (to get full native performance) - append a couple of light-weight servers as domU:s (like name server)
- Jussi Hirvi
I need to restructure my server farm from tower PC:s to a minimal amount of 1U rack servers. I am going to rely on xen virtualization, as KVM seems not to be very mature yet.
My current problem is the mail server, which uses a lot of CPU and I/O. A dedicated machine would be the best option. But would there be any sense in this:
- run the mail server in xen dom0 (to get full native performance)
- append a couple of light-weight servers as domU:s (like name server)
I don't know if it's recommended that way but at least it works fine.
Simon
On Fri, Mar 04, 2011 at 11:11:52AM +0200, Jussi Hirvi wrote:
On 4.3.2011 10.52, Simon Matter wrote:
I don't know if it's recommended that way but at least it works fine.
Hm, that is kind of the only important thing. :-)
If it is not recommended, there have to be better reasons for that than mere tidiness.
Dom0 should be reserved only for management toolstack and minimal amount of services (storage/network backends).
Actually dom0 is a *VM* aswell (see "xm list"), although it has more direct access to the hardware and thus to storage.
You're probably limited by the disk IOPS anyway, so it shouldn't matter that much if you run the service in dom0 or in domU, so go for domU, since that's the more safe bet.
-- Pasi
On Fri, Mar 04, 2011 at 11:37:08AM +0200, Pasi Kärkkäinen wrote:
On Fri, Mar 04, 2011 at 11:11:52AM +0200, Jussi Hirvi wrote:
On 4.3.2011 10.52, Simon Matter wrote:
I don't know if it's recommended that way but at least it works fine.
Hm, that is kind of the only important thing. :-)
If it is not recommended, there have to be better reasons for that than mere tidiness.
Dom0 should be reserved only for management toolstack and minimal amount of services (storage/network backends).
Actually dom0 is a *VM* aswell (see "xm list"), although it has more direct access to the hardware and thus to storage.
You're probably limited by the disk IOPS anyway, so it shouldn't matter that much if you run the service in dom0 or in domU, so go for domU, since that's the more safe bet.
Oh, you should also limit and dedicate fixed amount of memory for dom0, say, 768 MB, or whatever you need there.
http://wiki.xensource.com/xenwiki/XenBestPractices
-- Pasi
On Fri, 4 Mar 2011, Jussi Hirvi wrote:
I need to restructure my server farm from tower PC:s to a minimal amount of 1U rack servers. I am going to rely on xen virtualization, as KVM seems not to be very mature yet.
What part of KVM seems immature to you? I deploy public-facing machines using both it and Xen, and I can't really speak to any difference in performance or small-scall management.
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compdoc -
Jussi Hirvi -
Pasi Kärkkäinen -
Paul Heinlein -
Simon Matter