Re: [CentOS-virt] get xen name from guest
Hi,
how do you create the XEN-Config-File for your DomUs?
As with DHCP you could use the MAC-Address to identify your DomU, too.
Apart from that you may set the hostname during setup of the DomU.
I am using templates to generate new DomUs:
After copying the template with rsync into the LV for the new DomU (an LV in
Dom0 corresponds to a disk for the DomU) I modify the files where the hostname
resides (and statically setup the first network interface by filling in the
corresponding files of the DomU) before unmounting the LV again.
Are you really kickstarting each new DomU?
Kind regards
Nils
-Ursprüngliche Nachricht-
Von: centos-virt-boun...@centos.org
[mailto:centos-virt-boun...@centos.org] Im Auftrag von Ryan Pugatch
Gesendet: Mittwoch, 10. März 2010 14:16
An: Discussion about the virtualization on CentOS
Betreff: Re: [CentOS-virt] get xen name from guest
Christopher G. Stach II wrote:
- Ryan Pugatch r...@linux.com wrote:
Hello,
Is it possible to get the name that was set in a VM's xen
config file
from the guest machine? I'm interested in having my
kickstart launch
a script that can configure hostname, but to do that it
would need to
get the name set in the config.
Thanks,
Ryan
Since there isn't an rpm for the xenstore tools for guests,
copy libxenstore.so.* and /usr/bin/xenstore-read (and the
rest, if you want) to the guest and use something like this:
#!/bin/bash
let i=1
while [ $i -le 100 ]; do
NAME=$(./xenstore-read /local/domain/$i/name 2 /dev/null)
[ -n ${NAME} ] break
let i++
done
[ -n ${NAME} ] echo ${NAME}
exit 0
I don't see why you would even need this, though. If you
are using kickstart, you can get the hostname with either the
static configuration or DHCP.
The reason I want to do this is so I don't have to specify in
the kickstart the IP to use. With our Dell servers, for
example, I just add the service tag in to DNS and then the
server figures out what IP it is supposed to have.
Ryan
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Re: [CentOS-virt] moving from Xen to KVM
Hi, just two questions: 1. Is there anything faster than XEN-paravirtualization? 2. Why XEN 5? XEN 3 is quite stable, too. 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. I see no reason why I should move to KVM. My only limitation is memory, since RAM is not being virtually mapped yet. Kind regards Nils -Ursprüngliche Nachricht- Von: centos-virt-boun...@centos.org [mailto:centos-virt-boun...@centos.org] Im Auftrag von Christopher G. Stach II Gesendet: Freitag, 26. Februar 2010 09:04 An: Discussion about the virtualization on CentOS Betreff: Re: [CentOS-virt] moving from Xen to KVM [...] Here are a few tips: 1. F*** KVM. 2. Stick with Xen because there is quite a lot of time until 5 is EOL'd and if you haven't noticed, it's actually a mature technology. [...] ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Silly question about KVM
Scot P. Floess wrote: I was wondering, if I do not have hardware that natively supports full virtualization...and I choose to use KVM, You cannot use KVM on systems which do not support hardware virtualization will my VMs be running in some form of chip emulation (and therefore terribly slow). To date, I've been using Xen and am very comfortable with it. I have some fears that later whenever Xen is dropped - I'll have to consider KVM. Also, will Xen be carried forward should Xen be dropped from RHEL? xen will be included in RHEL 5 and hence in Centos 5 for the whole life of the distro. However it might (actually I am pretty sure this will happen) no longer get enhancements after a given time (but only bugfixes) ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Silly question about KVM
At some time, I thought I had gotten KVM working on one of my hosts - but was under the impression QEMU was used for emulation. It was some time ago...and was really me not knowing what I was doing...and tinkering. I could be completely wrong about this... On Wed, 17 Mar 2010, Manuel Wolfshant wrote: Scot P. Floess wrote: I was wondering, if I do not have hardware that natively supports full virtualization...and I choose to use KVM, You cannot use KVM on systems which do not support hardware virtualization will my VMs be running in some form of chip emulation (and therefore terribly slow). To date, I've been using Xen and am very comfortable with it. I have some fears that later whenever Xen is dropped - I'll have to consider KVM. Also, will Xen be carried forward should Xen be dropped from RHEL? xen will be included in RHEL 5 and hence in Centos 5 for the whole life of the distro. However it might (actually I am pretty sure this will happen) no longer get enhancements after a given time (but only bugfixes) ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt -- Scot P. Floess 27 Lake Royale Louisburg, NC 27549 252-478-8087 (Home) 919-890-8117 (Work) Chief Architect JPlate http://sourceforge.net/projects/jplate Chief Architect JavaPIM http://sourceforge.net/projects/javapim Architect Keros http://sourceforge.net/projects/keros ___ 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 02:15:52PM +0100, Hildebrand, Nils, 232 wrote: Hi, just two questions: 1. Is there anything faster than XEN-paravirtualization? 2. Why XEN 5? XEN 3 is quite stable, too. I guess you mean Citrix XenServer 5.5 with Xen 5 ? It's a completely different, full commercially supported product from Citrix, which has the opensource Xen hypervisor as a part of it. Actually it's based on CentOS. Citrix XenServer 5.x uses Xen 3.x hypervisor. 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. Yeah, Linux PV guests perform and work OK. -- Pasi I have no problem with disk IO-Bottlenecks since my DomUs are not Database-Servers - so there is mostly static information in the filesystems. I see no reason why I should move to KVM. My only limitation is memory, since RAM is not being virtually mapped yet. Kind regards Nils -Ursprüngliche Nachricht- Von: centos-virt-boun...@centos.org [mailto:centos-virt-boun...@centos.org] Im Auftrag von Christopher G. Stach II Gesendet: Freitag, 26. Februar 2010 09:04 An: Discussion about the virtualization on CentOS Betreff: Re: [CentOS-virt] moving from Xen to KVM [...] Here are a few tips: 1. F*** KVM. 2. Stick with Xen because there is quite a lot of time until 5 is EOL'd and if you haven't noticed, it's actually a mature technology. [...] ___ 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] Silly question about KVM
On Wed, Mar 17, 2010 at 09:42:34AM -0400, Scot P. Floess wrote: I was wondering, if I do not have hardware that natively supports full virtualization...and I choose to use KVM, will my VMs be running in some form of chip emulation (and therefore terribly slow). To date, I've been using Xen and am very comfortable with it. I have some fears that later whenever Xen is dropped - I'll have to consider KVM. Xen is part of RHEL5. RHEL5 will be supported until 2014. So Xen will be supported in RHEL5 until 2014. Redhat has stated this many times. Also, will Xen be carried forward should Xen be dropped from RHEL? RHEL6 will run as Xen guest/domU, even if RHEL6 won't have Xen dom0 support. Upstream Xen development is very active, so no worries there either. -- Pasi -- Scot P. Floess 27 Lake Royale Louisburg, NC 27549 252-478-8087 (Home) 919-890-8117 (Work) Chief Architect JPlate http://sourceforge.net/projects/jplate Chief Architect JavaPIM http://sourceforge.net/projects/javapim Architect Keros http://sourceforge.net/projects/keros ___ 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] Silly question about KVM
Sure, I understand the support until 2014...was more thinking of moving to 6 and beyond... On Wed, 17 Mar 2010, Pasi Kärkkäinen wrote: On Wed, Mar 17, 2010 at 09:42:34AM -0400, Scot P. Floess wrote: I was wondering, if I do not have hardware that natively supports full virtualization...and I choose to use KVM, will my VMs be running in some form of chip emulation (and therefore terribly slow). To date, I've been using Xen and am very comfortable with it. I have some fears that later whenever Xen is dropped - I'll have to consider KVM. Xen is part of RHEL5. RHEL5 will be supported until 2014. So Xen will be supported in RHEL5 until 2014. Redhat has stated this many times. Also, will Xen be carried forward should Xen be dropped from RHEL? RHEL6 will run as Xen guest/domU, even if RHEL6 won't have Xen dom0 support. Upstream Xen development is very active, so no worries there either. -- Pasi -- Scot P. Floess 27 Lake Royale Louisburg, NC 27549 252-478-8087 (Home) 919-890-8117 (Work) Chief Architect JPlate http://sourceforge.net/projects/jplate Chief Architect JavaPIM http://sourceforge.net/projects/javapim Architect Keros http://sourceforge.net/projects/keros ___ 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 -- Scot P. Floess 27 Lake Royale Louisburg, NC 27549 252-478-8087 (Home) 919-890-8117 (Work) Chief Architect JPlate http://sourceforge.net/projects/jplate Chief Architect JavaPIM http://sourceforge.net/projects/javapim Architect Keros http://sourceforge.net/projects/keros___ 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 sflo...@nc.rr.com 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] moving from Xen to KVM
On Wed, Mar 17, 2010 at 6:35 AM, Dennis J. denni...@conversis.de 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
