Hi!
I have the following problem: I have a server (CentOS 5.3 x86_64) on which I want to install a virtual Xen-machine (CentOS 5.3 x86_64), I ssh from my workstation (Centos 5.3 x86_64 .... do you see the pattern ;) ) to that server and start the virt-manager. I create a new Guest (Paravirtualiuzed) and point it to the server with the installation files (CentOS 5.3, but I already said that). The manager creates the disk image an then opens the Graphical console for installation. Sometime around the point where the installation program wants me to select the keyboard the graphical console it freezes. The server is completely dead (no console, no disk activity, no ping, only a reset will "repair" it)
My question: am I doing something stupid? But I figured "They're all the same system, this must work"
I don't want to play around with it too much as the server is also our file-server and people start complaining.
So any hint will be greatly appreciated (otherwise I'll have to setup another machine for the guests)
Bernhard
----- Original Message ----
From: Bernhard Gschaider bgschaid_lists@ice-sf.at To: centos@centos.org Sent: Tuesday, 18 August, 2009 18:56:36 Subject: [CentOS] virt-manager crashes Host during installation of guest
Hi!
I have the following problem: I have a server (CentOS 5.3 x86_64) on which I want to install a virtual Xen-machine (CentOS 5.3 x86_64), I ssh from my workstation (Centos 5.3 x86_64 .... do you see the pattern ;) ) to that server and start the virt-manager. I create a new Guest (Paravirtualiuzed) and point it to the server with the installation files (CentOS 5.3, but I already said that). The manager creates the disk image an then opens the Graphical console for installation. Sometime around the point where the installation program wants me to select the keyboard the graphical console it freezes. The server is completely dead (no console, no disk activity, no ping, only a reset will "repair" it)
My question: am I doing something stupid? But I figured "They're all the same system, this must work"
I don't want to play around with it too much as the server is also our file-server and people start complaining.
So any hint will be greatly appreciated (otherwise I'll have to setup another machine for the guests)
Personally, I use the technique described in the Wiki - http://wiki.centos.org/HowTos/Xen/InstallingCentOSDomU
It has worked flawlessly for me every time. Once you have one install config file and one for running, you can easily make copies to accommodate extra guests. You don't have to do the kickstart bit if you're happy to select your options at install time, like a normal install.
When I did first use virt-manager, it seemed okay. I didn't want to become dependent on a GUI tool, though.
xen-user list is a good place for further Xen specific advice.
I would also recommend using the Xen hypervisor and tools at the gitco repository. http://www.gitco.de/repo/
Bernhard Gschaider wrote on Tue, 18 Aug 2009 19:56:36 +0200:
My question: am I doing something stupid? But I figured "They're all the same system, this must work"
I don't want to play around with it too much as the server is also our file-server and people start complaining.
So any hint will be greatly appreciated (otherwise I'll have to setup another machine for the guests)
Can't help with figuring out the virt-manager problem. My first steps with Xen where with virt-manager, but that's been a long time ago (and it worked fine back then). I haven't looked at it since then. You simply don't need it, usually you don't want to run any X on a server.
virt-install works fine, is command-line and you can either have it ask for all the parameters or you can provide all of them, so it's a "one command" installation.
Kai
Bernhard Gschaider wrote:
Hi!
I have the following problem: I have a server (CentOS 5.3 x86_64) on which I want to install a virtual Xen-machine (CentOS 5.3 x86_64), I ssh from my workstation (Centos 5.3 x86_64 .... do you see the pattern ;) ) to that server and start the virt-manager. I create a new Guest (Paravirtualiuzed) and point it to the server with the installation files (CentOS 5.3, but I already said that). The manager creates the disk image an then opens the Graphical console for installation. Sometime around the point where the installation program wants me to select the keyboard the graphical console it freezes. The server is completely dead (no console, no disk activity, no ping, only a reset will "repair" it)
My question: am I doing something stupid? But I figured "They're all the same system, this must work"
I don't want to play around with it too much as the server is also our file-server and people start complaining.
So any hint will be greatly appreciated (otherwise I'll have to setup another machine for the guests)
Bernhard
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Hi
I use the virt-manager, but I always use a kickstart to do the installation and I never had problems.
Regards
mg.
Thanks for the replies so far.
On Wed, 19 Aug 2009 11:06:08 +0100 "MMG" == Marcelo M Garcia marcelo.maia.garcia@googlemail.com wrote:
MMG> Bernhard Gschaider wrote: >> Hi! >> >> I have the following problem: I have a server (CentOS 5.3 >> x86_64) on which I want to install a virtual Xen-machine >> (CentOS 5.3 x86_64), I ssh from my workstation (Centos 5.3 >> x86_64 .... do you see the pattern ;) ) to that server and >> start the virt-manager. I create a new Guest (Paravirtualiuzed) >> and point it to the server with the installation files (CentOS >> 5.3, but I already said that). The manager creates the disk >> image an then opens the Graphical console for >> installation. Sometime around the point where the installation >> program wants me to select the keyboard the graphical console >> it freezes. The server is completely dead (no console, no disk >> activity, no ping, only a reset will "repair" it) >> >> My question: am I doing something stupid? But I figured >> "They're all the same system, this must work" >> >> I don't want to play around with it too much as the server is >> also our file-server and people start complaining. >> >> So any hint will be greatly appreciated (otherwise I'll have to >> setup another machine for the guests) >>
MMG> I use the virt-manager, but I always use a kickstart to do MMG> the installation and I never had problems.
This (and other replies) lead me to two possible culprits: - either the graphical console over X11 is not a good idea (but I can't imagine that, it shouldn't shoot the kernel) - I always installed as a paravirtualized machine, Could it be that the install-kernel on the 5.3-media is not aware of this and somehow manages to shot the host (because I noticed that most recipies on the net, including http://wiki.centos.org/HowTos/Xen/InstallingCentOSDomU never talk about paravirtualized (so I assume they use a fully virtualized guest)
I will try these later today (when people left the office and no one will complain about server downtimes)
Bernhard
BTW: Just one fundamental question: as the upstream OS vendor is switching his virtualization to KVM anyway, is it a good idea to forget Xen and use KVM (in other words: is it stable enough for production)?
On Aug 19, 2009, at 7:52 AM, Bernhard Gschaider <bgschaid_lists@ice-sf.at
wrote:
Thanks for the replies so far.
On Wed, 19 Aug 2009 11:06:08 +0100 "MMG" == Marcelo M Garcia marcelo.maia.garcia@googlemail.com wrote:
MMG> Bernhard Gschaider wrote:
Hi!
I have the following problem: I have a server (CentOS 5.3 x86_64) on which I want to install a virtual Xen-machine (CentOS 5.3 x86_64), I ssh from my workstation (Centos 5.3 x86_64 .... do you see the pattern ;) ) to that server and start the virt-manager. I create a new Guest (Paravirtualiuzed) and point it to the server with the installation files (CentOS 5.3, but I already said that). The manager creates the disk image an then opens the Graphical console for installation. Sometime around the point where the installation program wants me to select the keyboard the graphical console it freezes. The server is completely dead (no console, no disk activity, no ping, only a reset will "repair" it)
My question: am I doing something stupid? But I figured "They're all the same system, this must work"
I don't want to play around with it too much as the server is also our file-server and people start complaining.
So any hint will be greatly appreciated (otherwise I'll have to setup another machine for the guests)
MMG> I use the virt-manager, but I always use a kickstart to do MMG> the installation and I never had problems.
This (and other replies) lead me to two possible culprits:
- either the graphical console over X11 is not a good idea (but I can't imagine that, it shouldn't shoot the kernel)
- I always installed as a paravirtualized machine, Could it be that the install-kernel on the 5.3-media is not aware of this and somehow manages to shot the host (because I noticed that most recipies on
the net, including http://wiki.centos.org/HowTos/Xen/ InstallingCentOSDomU never talk about paravirtualized (so I assume they use a fully virtualized guest)
I will try these later today (when people left the office and no one will complain about server downtimes)
Bernhard
BTW: Just one fundamental question: as the upstream OS vendor is switching his virtualization to KVM anyway, is it a good idea to forget Xen and use KVM (in other words: is it stable enough for production)?
Xen still has it's place as it's fully paravirtualized domains are still way faster then any fully virtualized setups.
Plus it's the only hypervisor I know of that let's you pass-through just about any PCI device to a domU.
Once VMware gets their pass-through generalized and Intel gets their next generation hardware virtualization technology mainstreamed, Xen won't have such an edge in those areas.
I still have yet to see a VMware/KVM framework for cloud computing where VMs can be seemlessly transferred between hosts or even to an off-site virtualization provider.
-Ross
This (and other replies) lead me to two possible culprits:
- either the graphical console over X11 is not a good idea (but I can't imagine that, it shouldn't shoot the kernel)
- I always installed as a paravirtualized machine, Could it be that the install-kernel on the 5.3-media is not aware of this and somehow manages to shot the host (because I noticed that most recipies on
the net, including http://wiki.centos.org/HowTos/Xen/ InstallingCentOSDomU never talk about paravirtualized (so I assume they use a fully virtualized guest)
I will try these later today (when people left the office and no one will complain about server downtimes)
Bernhard
BTW: Just one fundamental question: as the upstream OS vendor is switching his virtualization to KVM anyway, is it a good idea to forget Xen and use KVM (in other words: is it stable enough for production)?
Sorry for thread mucking. I did not receive this email, but took it from a response.
The Xen wiki describes a paravirtual install. The config file would have a line like builder="hvm" if it was fully virtualised guest. AFAIK the graphical view is just a VNC session, so I would be surprised if that managed to trash your kernel. More likely it's something that the guest is doing that is causing the issue. You could always prepare your guests on a different machine and transfer them later. Ofcourse, if you had a command of xm, that is.
As I said before, I would recommend the xen list for this specific issue.
As for the Xen vs whatever issue, I was disappointed when it became clear that Upstream was going to push another technology, having spent last year or two trying to learn Xen (and I am no expert, at all). Having said that, I've heard of issues with speed with KVM and I haven't had any such issues with Xen. My only issue with Xen is that the official releases are based on quite an old kernel, which is fine for CentOS, bc it is the same as the vanilla kernel. Anecdotally, a lot of issues on the xen list IMHO seem to arise from ppl using later patched kernels, which perhaps isn't the best route for stability.
Thanks to everyone who took the time to answer in this thread.
I'm just writing this message to give this thread some closure and am not expecting any answers
On Wed, 19 Aug 2009 10:29:33 -0700 (PDT) "IM" == Ian Murray murrayie@yahoo.co.uk wrote:
>> > This (and other replies) lead me to two possible culprits: > >> - either the graphical console over X11 is not a good idea (but >> I > can't imagine that, it shouldn't shoot the kernel) > - I >> always installed as a paravirtualized machine, Could it be that >> > the install-kernel on the 5.3-media is not aware of this and >> somehow > manages to shot the host (because I noticed that most >> recipies on > the > net, including >> http://wiki.centos.org/HowTos/Xen/ > InstallingCentOSDomU > >> never talk about paravirtualized (so I assume they use a fully >> > virtualized guest) >> > >> > I will try these later today (when people left the office and >> no one > will complain about server downtimes) >> > >> > Bernhard >> > >> > BTW: Just one fundamental question: as the upstream OS vendor >> is > switching his virtualization to KVM anyway, is it a good >> idea to > forget Xen and use KVM (in other words: is it stable >> enough for > production)?
IM> Sorry for thread mucking. I did not receive this email, but IM> took it from a response.
IM> The Xen wiki describes a paravirtual install. The config file IM> would have a line like builder="hvm" if it was fully IM> virtualised guest. AFAIK the graphical view is just a VNC IM> session, so I would be surprised if that managed to trash your IM> kernel. More likely it's something that the guest is doing IM> that is causing the issue. You could always prepare your IM> guests on a different machine and transfer them IM> later. Ofcourse, if you had a command of xm, that is.
I tried removing both suspects by
- following the Wiki-Howto to the letter (especially using the Xen-install-kernels) - instead of going over the network I worked directly at the machine (although I totally agree that a VNC-session shouldn't be ble to shoot the machine)
but the problem is still there. When I start the configured machine that points to an install-kernel with
xm create newGuest -c
I see the kernel boot up until it comes to the message
Write protecting the kernel read-only data
where it hangs for some seconds, then the screen goes blank and the machine reboots.
I'm starting to suspect that it is somehow hardware-related (it is a Fujitsu-Siemens Synergy server with a RAID-controller) and I will investigate in that direction
IM> As I said before, I would recommend the xen list for this IM> specific issue.
Will look there to, thanks
IM> As for the Xen vs whatever issue, I was disappointed when it IM> became clear that Upstream was going to push another IM> technology, having spent last year or two trying to learn Xen IM> (and I am no expert, at all). Having said that, I've heard of IM> issues with speed with KVM and I haven't had any such issues IM> with Xen. My only issue with Xen is that the official releases IM> are based on quite an old kernel, which is fine for CentOS, bc IM> it is the same as the vanilla kernel. Anecdotally, a lot of IM> issues on the xen list IMHO seem to arise from ppl using later IM> patched kernels, which perhaps isn't the best route for IM> stability.
As I'm using the latest kernel that comes with the 5.3-updates and the machine has nothing but the standard-5.3 stuff on it, I don't think this is the case
Bernhard
Bernhard Gschaider wrote on Thu, 20 Aug 2009 01:47:07 +0200:
- following the Wiki-Howto to the letter (especially using the Xen-install-kernels)
Again, I think this is the wrong way to go, it's outdated. I've never done it this way and I think this How-To is derived from very old Xen versions and got updated a few times over time without changing the basics. It *may* work, but it's complicated to follow and overly complex, e.g. you can very easily make a tiny mistake and never get going which is highly frustrating.
As I wrote, just do a "virt-install -p" and that's all. No "install kernels", no creation of an image file, no nothing. virt-install will do everything for you. Once the VM has been setup and saved you can create a config-file and put it in /etc/xen and then "xm create" the machine. Straight-forward and easy. The config-file is going to look like this: name = "d-mini" maxmem = 128 memory = 128 vcpus = 1 bootloader = "/usr/bin/pygrub" on_poweroff = "destroy" on_reboot = "restart" on_crash = "restart" #vfb = [ "type=vnc,vncdisplay=12,vncunused=1" ] disk = [ "file:/home2/vm/d-minimal.img,xvda,w"] vif = [ "mac=00:16:3e:43:18:13" ]
And if you prefer kickstart a (replace with your own data)
virt-install -p --location=ftp://.... --noautoconsole --nographics -- file=/.../d-minimal.img --file-size=1 --name=d-mini --ram=256 -x "ks=ftp://.../minimal-file.ks ip=192.168.1.* netmask=255.255.255.0 dns=192.168.1.* gateway=192.168.1.*"
gets you in business in less than 10 minutes without any manual intervention.
Kai
Again, I think this is the wrong way to go, it's outdated. I've never done it this way and I think this How-To is derived from very old Xen versions and got updated a few times over time without changing the basics. It *may* work, but it's complicated to follow and overly complex, e.g. you can very easily make a tiny mistake and never get going which is highly frustrating.
Actual, virt-install commmand line looks no less daunting to me. The Wiki described method should work for all RH derived distributions that are Xen PV compatible. I tried SME (or it might have been Trixbox... or both!) and it installed okay, but the kernel wasn't happy in a Xen world. Could fix it, but was lazy and used hardware virtualisation. Personally, I prefer to keep swap on a seperate partition, as it makes it easier to mount root. I don't know if that is possible under virt-install.
To be honest, I don't really think there are too many shortcuts with Xen, because it pays to understand how it works at a lower level, how to mount loopbacks, even with LVM's inside them, etc. I can't really remember the options under virt-install, but if they do 'dumb things down', then that may not be helpful in the long run.
Anyway, both ways are way more friendly than debootstrapping your Debian system. ;o)
disk = [ "file:/home2/vm/d-minimal.img,xvda,w"]
I think tap:aio is more favoured than file, for performance reasons.
Ian Murray wrote on Thu, 20 Aug 2009 14:21:33 +0000 (GMT):
Actual, virt-install commmand line looks no less daunting to me.
What is "daunting" about "virt-install -p"?
I don't know if that is possible under virt-install.
Everything is possible, it depends on how deep you want to dig into it. This guy just wants to get his first Xen VM up for some testing (I suppose). There is no need to follow lengthy explanations and fail in the end if there is a simple command available.
I think tap:aio is more favoured than file, for performance reasons.
This is general belief. I suggest doing some tests. After that you may think different. ;-) Also, there have been various problems with tap:aio devices in the various Xen incarnations over time that weren't present in file. You want to use LVM or remote storage for real world usage, anyway, but that wasn't the task outlined by the OP.
Kai
I definitely think if your new to Xen and are use to doing normal CD installs, then virt-install is the easiest way to go.
Also, you could consider using prebuilt images that are already made depending on your needs. These can be found on stacklet.com.
Hope that helps, Matt
-- Mathew S. McCarrell Clarkson University '10
mccarrms@gmail.com mccarrms@clarkson.edu 1-518-314-9214
On Thu, Aug 20, 2009 at 2:31 PM, Kai Schaetzl maillists@conactive.comwrote:
Ian Murray wrote on Thu, 20 Aug 2009 14:21:33 +0000 (GMT):
Actual, virt-install commmand line looks no less daunting to me.
What is "daunting" about "virt-install -p"?
I don't know if that is possible under virt-install.
Everything is possible, it depends on how deep you want to dig into it. This guy just wants to get his first Xen VM up for some testing (I suppose). There is no need to follow lengthy explanations and fail in the end if there is a simple command available.
I think tap:aio is more favoured than file, for performance reasons.
This is general belief. I suggest doing some tests. After that you may think different. ;-) Also, there have been various problems with tap:aio devices in the various Xen incarnations over time that weren't present in file. You want to use LVM or remote storage for real world usage, anyway, but that wasn't the task outlined by the OP.
Kai
-- Kai Schätzl, Berlin, Germany Get your web at Conactive Internet Services: http://www.conactive.com
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
----- Original Message ----
From: Kai Schaetzl maillists@conactive.com To: centos@centos.org Sent: Thursday, 20 August, 2009 19:31:21 Subject: Re: [CentOS] virt-manager crashes Host during installation of guest
Ian Murray wrote on Thu, 20 Aug 2009 14:21:33 +0000 (GMT):
Actual, virt-install commmand line looks no less daunting to me.
What is "daunting" about "virt-install -p"?
[root@xen ~]# virt-install -p ERROR A name is required for the virtual machine. [root@xen ~]# virt-install -p -n newdom ERROR Memory amount is required for the virtual machine. [root@xen ~]# virt-install -p -n newdom -r 256 ERROR A disk must be specified (use --nodisks to override)
So it goes on... I suppose once you plough through all the options and save the whole command somewhere, then it is trivial to create new ones, but I got the impression that it was interactive for any missing options.
Perhaps for the benefit of the OP, perhaps you could give a complete known working example.
I don't know if that is possible under virt-install.
Everything is possible, it depends on how deep you want to dig into it. This guy just wants to get his first Xen VM up for some testing (I suppose). There is no need to follow lengthy explanations and fail in the end if there is a simple command available.
I think tap:aio is more favoured than file, for performance reasons.
This is general belief. I suggest doing some tests. After that you may think different. ;-) Also, there have been various problems with tap:aio devices in the various Xen incarnations over time that weren't present in file.
Well, if you have done such tests, please do share... especially on the xen-users list, as there are far more competent Xen-ers to discuss your findings than me.
You want to use LVM or remote storage for real world usage, anyway, but that wasn't the task outlined by the OP.
File based domains initially seemed the simplest way for me, but after a while I concluded they were a but of a pain actually, so indeed I do stick with LVs.
virt-install can be interactive if you supply a few necessary options first. I've put a sample of what I normally do below.
[root@dom0 ~]$ /usr/sbin/virt-install -p --nonsparse -b xenbr0
What is the name of your virtual machine? <VM NAME HERE> How much RAM should be allocated (in megabytes)? 256 What would you like to use as the disk (path)? /xen/images/<VM NAME HERE>.disk
How large would you like the disk (/xen/images/<VM NAME HERE>) to be (in gigabytes)? 5
Would you like to enable graphics support? (yes or no) no What is the install location? http://mirror.clarkson.edu/centos/5.3/os/x86_64/
Also, if your willing to spend a few bucks, the Running Xen book is a great source of information for anything relating to Xen (and I'm not saying that just because I'm friends with several of the authors). Also, you might find the following slides useful. http://cosi.clarkson.edu/docs/installingxen/
-- Mathew S. McCarrell Clarkson University '10
mccarrms@gmail.com mccarrms@clarkson.edu 1-518-314-9214
On Thu, Aug 20, 2009 at 10:09 PM, Ian Murray murrayie@yahoo.co.uk wrote:
----- Original Message ----
From: Kai Schaetzl maillists@conactive.com To: centos@centos.org Sent: Thursday, 20 August, 2009 19:31:21 Subject: Re: [CentOS] virt-manager crashes Host during installation of
guest
Ian Murray wrote on Thu, 20 Aug 2009 14:21:33 +0000 (GMT):
Actual, virt-install commmand line looks no less daunting to me.
What is "daunting" about "virt-install -p"?
[root@xen ~]# virt-install -p ERROR A name is required for the virtual machine. [root@xen ~]# virt-install -p -n newdom ERROR Memory amount is required for the virtual machine. [root@xen ~]# virt-install -p -n newdom -r 256 ERROR A disk must be specified (use --nodisks to override)
So it goes on... I suppose once you plough through all the options and save the whole command somewhere, then it is trivial to create new ones, but I got the impression that it was interactive for any missing options.
Perhaps for the benefit of the OP, perhaps you could give a complete known working example.
I don't know if that is possible under virt-install.
Everything is possible, it depends on how deep you want to dig into it.
This guy
just wants to get his first Xen VM up for some testing (I suppose). There
is no
need to follow lengthy explanations and fail in the end if there is a
simple
command available.
I think tap:aio is more favoured than file, for performance reasons.
This is general belief. I suggest doing some tests. After that you may
think
different. ;-) Also, there have been various problems with tap:aio
devices in
the various Xen incarnations over time that weren't present in file.
Well, if you have done such tests, please do share... especially on the xen-users list, as there are far more competent Xen-ers to discuss your findings than me.
You want to use LVM or remote storage for real world usage, anyway, but
that
wasn't the task outlined by the OP.
File based domains initially seemed the simplest way for me, but after a while I concluded they were a but of a pain actually, so indeed I do stick with LVs.
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Ian Murray wrote on Fri, 21 Aug 2009 02:09:04 +0000 (GMT):
[root@xen ~]# virt-install -p ERROR A name is required for the virtual machine.
Oh, my god. I just gave this extra parameter as I thought it would then ask for the missing data. I forgot that you can either have interactive or parameters, not a mix. You run just "virt-install" then. That's even more "daunting", is it? I suppose that was too difficult to figure out yourself?
Perhaps for the benefit of the OP, perhaps you could give a complete known working example.
Hm, surprise, surprise, I gave one.
Well, if you have done such tests, please do share... especially on the xen-users list, as there are far more competent Xen-ers to discuss your findings than me.
Read it's archives.
Kai
----- Original Message ----
From: Kai Schaetzl maillists@conactive.com To: centos@centos.org Sent: Friday, 21 August, 2009 10:31:22 Subject: Re: [CentOS] virt-manager crashes Host during installation of guest
Ian Murray wrote on Fri, 21 Aug 2009 02:09:04 +0000 (GMT):
[root@xen ~]# virt-install -p ERROR A name is required for the virtual machine.
Oh, my god. I just gave this extra parameter as I thought it would then ask for the missing data. I forgot that you can either have interactive or parameters, not a mix. You run just "virt-install" then. That's even more "daunting", is it? I suppose that was too difficult to figure out yourself?
I never used virt-install and you were going on about how easy it was. Even you managed to get it wrong. You forgot and I never knew. I just copied and pasted what you stated several times would work. As a newbie would. ;o) As I said before, I am pretty *happy* with the way I create my VMs, and this thread isn't about how I create them. Getting a massive command-line right can be daunting, if you are new to the technology. That's just my opinion.
Perhaps for the benefit of the OP, perhaps you could give a complete known
working example.
Hm, surprise, surprise, I gave one.
Okay, I didn't recall, my bad.
Well, if you have done such tests, please do share... especially on the xen-users list, as there are far more competent Xen-ers to discuss your findings than me.
Read it's archives.
Thanks, very helpful. I guess that means 'read it in the archives.' I am sure it is easy to find.
Kai
-- Kai Schätzl, Berlin, Germany Get your web at Conactive Internet Services: http://www.conactive.com
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On Thu, 20 Aug 2009 01:47:07 +0200 "BG" == Bernhard Gschaider bgschaid_lists@ice-sf.at wrote:
BG> Thanks to everyone who took the time to answer in this thread.
BG> I'm just writing this message to give this thread some closure BG> and am not expecting any answers
I found the cause of my problem. I'll answer to my own posting, because none of the follow-ups lead to the solution, the reason being that I withheld some vital information for the diagnosis:
The filesystem which the disk-image for the virtual machine resides on is XFS!
Googling around I found indications that there are indications that XEN and XFS are not the best of friends, but nobody hinted at something as drastic as completely freezing the host.
Anyway. When I create the image on an ext3-partition and point the configuration to it (no other changes) the installation works without problems.
Bernhard
PS: There were speculations in the replies, that this was my first Xen-experience. I want to stress that I have already a running Xen-machine, that's why I was surprised that it didn't work this time (but I set that one up a year ago, so technically I am starting anew with Xen and the speculations are right)
On Wed, 19 Aug 2009 10:29:33 -0700 (PDT) "IM" == Ian Murray murrayie@yahoo.co.uk wrote:
>>> > This (and other replies) lead me to two possible culprits: > >>> - either the graphical console over X11 is not a good idea >>> (but I > can't imagine that, it shouldn't shoot the kernel) > >>> - I always installed as a paravirtualized machine, Could it be >>> that > the install-kernel on the 5.3-media is not aware of >>> this and somehow > manages to shot the host (because I noticed >>> that most recipies on > the > net, including >>> http://wiki.centos.org/HowTos/Xen/ > InstallingCentOSDomU > >>> never talk about paravirtualized (so I assume they use a fully >>> > virtualized guest) >>> > >>> > I will try these later today (when people left the office >>> and no one > will complain about server downtimes) >>> > >>> > Bernhard >>> > >>> > BTW: Just one fundamental question: as the upstream OS >>> vendor is > switching his virtualization to KVM anyway, is it >>> a good idea to > forget Xen and use KVM (in other words: is it >>> stable enough for > production)?
BG> I tried removing both suspects by
BG> - following the Wiki-Howto to the letter (especially using BG> the Xen-install-kernels) - instead of going over the network I BG> worked directly at the machine (although I totally agree that BG> a VNC-session shouldn't be ble to shoot the machine)
BG> but the problem is still there. When I start the configured BG> machine that points to an install-kernel with
BG> xm create newGuest -c
BG> I see the kernel boot up until it comes to the message
BG> Write protecting the kernel read-only data
BG> where it hangs for some seconds, then the screen goes blank BG> and the machine reboots.
BG> I'm starting to suspect that it is somehow hardware-related BG> (it is a Fujitsu-Siemens Synergy server with a BG> RAID-controller) and I will investigate in that direction
On Mon, Aug 24, 2009 at 06:04:06PM +0200, Bernhard Gschaider wrote:
On Thu, 20 Aug 2009 01:47:07 +0200 "BG" == Bernhard Gschaider bgschaid_lists@ice-sf.at wrote:
BG> Thanks to everyone who took the time to answer in this thread. BG> I'm just writing this message to give this thread some closure BG> and am not expecting any answersI found the cause of my problem. I'll answer to my own posting, because none of the follow-ups lead to the solution, the reason being that I withheld some vital information for the diagnosis:
The filesystem which the disk-image for the virtual machine resides on is XFS!
Googling around I found indications that there are indications that XEN and XFS are not the best of friends, but nobody hinted at something as drastic as completely freezing the host.
Anyway. When I create the image on an ext3-partition and point the configuration to it (no other changes) the installation works without problems.
Are you running 32bit or 64bit Xen host/dom0?
XFS is known to have problems on 32bit kernels, while it should work on 64bit kernels. (this is even without Xen).
-- Pasi
Bernhard
PS: There were speculations in the replies, that this was my first Xen-experience. I want to stress that I have already a running Xen-machine, that's why I was surprised that it didn't work this time (but I set that one up a year ago, so technically I am starting anew with Xen and the speculations are right)
On Wed, 19 Aug 2009 10:29:33 -0700 (PDT) "IM" == Ian Murray murrayie@yahoo.co.uk wrote:
>>> > This (and other replies) lead me to two possible culprits: > >>> - either the graphical console over X11 is not a good idea >>> (but I > can't imagine that, it shouldn't shoot the kernel) > >>> - I always installed as a paravirtualized machine, Could it be >>> that > the install-kernel on the 5.3-media is not aware of >>> this and somehow > manages to shot the host (because I noticed >>> that most recipies on > the > net, including >>> http://wiki.centos.org/HowTos/Xen/ > InstallingCentOSDomU > >>> never talk about paravirtualized (so I assume they use a fully >>> > virtualized guest) >>> > >>> > I will try these later today (when people left the office >>> and no one > will complain about server downtimes) >>> > >>> > Bernhard >>> > >>> > BTW: Just one fundamental question: as the upstream OS >>> vendor is > switching his virtualization to KVM anyway, is it >>> a good idea to > forget Xen and use KVM (in other words: is it >>> stable enough for > production)? BG> I tried removing both suspects by BG> - following the Wiki-Howto to the letter (especially using BG> the Xen-install-kernels) - instead of going over the network I BG> worked directly at the machine (although I totally agree that BG> a VNC-session shouldn't be ble to shoot the machine) BG> but the problem is still there. When I start the configured BG> machine that points to an install-kernel with BG> xm create newGuest -c BG> I see the kernel boot up until it comes to the message BG> Write protecting the kernel read-only data BG> where it hangs for some seconds, then the screen goes blank BG> and the machine reboots. BG> I'm starting to suspect that it is somehow hardware-related BG> (it is a Fujitsu-Siemens Synergy server with a BG> RAID-controller) and I will investigate in that direction--
DI Bernhard F.W. Gschaider
EMail: Bernhard.Gschaider@ice-sf.at WWW : www.ice-sf.at Jabber : bgschaid@jabber.org Tel: +43(3842)98282-42 Fax: +43(3842)98282-02
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On Mon, 24 Aug 2009 20:43:57 +0300 "PK" == Pasi Kärkkäinen pasik@iki.fi wrote:
PK> On Mon, Aug 24, 2009 at 06:04:06PM +0200, Bernhard Gschaider PK> wrote: >> >>>>> On Thu, 20 Aug 2009 01:47:07 +0200 >> >>>>> "BG" == Bernhard Gschaider bgschaid_lists@ice-sf.at wrote: >> BG> Thanks to everyone who took the time to answer in this thread. >> BG> I'm just writing this message to give this thread some closure BG> and am not expecting any answers >> I found the cause of my problem. I'll answer to my own posting, >> because none of the follow-ups lead to the solution, the reason >> being that I withheld some vital information for the diagnosis: >> >> The filesystem which the disk-image for the virtual machine >> resides on is XFS! >> >> Googling around I found indications that there are indications >> that XEN and XFS are not the best of friends, but nobody hinted >> at something as drastic as completely freezing the host. >> >> Anyway. When I create the image on an ext3-partition and point >> the configuration to it (no other changes) the installation >> works without problems. >>
PK> Are you running 32bit or 64bit Xen host/dom0?
PK> XFS is known to have problems on 32bit kernels, while it PK> should work on 64bit kernels. (this is even without Xen).
Everything is 64 bit. So that can't be the explanation.
PK> -- Pasi
>> Bernhard >> >> PS: There were speculations in the replies, that this was my >> first Xen-experience. I want to stress that I have already a >> running Xen-machine, that's why I was surprised that it didn't >> work this time (but I set that one up a year ago, so >> technically I am starting anew with Xen and the speculations >> are right) >> >> >>>>> On Wed, 19 Aug 2009 10:29:33 -0700 (PDT) >> >>>>> "IM" == Ian Murray murrayie@yahoo.co.uk wrote: >> >> >>> > This (and other replies) lead me to two possible >> culprits: > >>> - either the graphical console over X11 is not >> a good idea >>> (but I > can't imagine that, it shouldn't shoot >> the kernel) > >>> - I always installed as a paravirtualized >> machine, Could it be >>> that > the install-kernel on the >> 5.3-media is not aware of >>> this and somehow > manages to >> shot the host (because I noticed >>> that most recipies on > >> the > net, including >>> http://wiki.centos.org/HowTos/Xen/ > >> InstallingCentOSDomU > >>> never talk about paravirtualized (so >> I assume they use a fully >>> > virtualized guest) >> >>> > >> >>> > I will try these later today (when people left the office >> >>> and no one > will complain about server downtimes) >> >>> > >> >>> > Bernhard >> >>> > >> >>> > BTW: Just one fundamental question: as the upstream OS >> >>> vendor is > switching his virtualization to KVM anyway, is >> it >>> a good idea to > forget Xen and use KVM (in other words: >> is it >>> stable enough for > production)? >> BG> I tried removing both suspects by >> BG> - following the Wiki-Howto to the letter (especially using the BG> Xen-install-kernels) - instead of going over the network I BG> worked directly at the machine (although I totally agree that BG> a VNC-session shouldn't be ble to shoot the machine) >> BG> but the problem is still there. When I start the configured BG> machine that points to an install-kernel with >> BG> xm create newGuest -c >> BG> I see the kernel boot up until it comes to the message >> BG> Write protecting the kernel read-only data >> BG> where it hangs for some seconds, then the screen goes blank BG> and the machine reboots. >> BG> I'm starting to suspect that it is somehow hardware-related BG> (it is a Fujitsu-Siemens Synergy server with a BG> RAID-controller) and I will investigate in that direction >> >> >> -- >> --------------------------------------------------------------------------- >> DI Bernhard F.W. Gschaider >> --------------------------------------------------------------------------- >> EMail: Bernhard.Gschaider@ice-sf.at WWW : www.ice-sf.at Jabber >> : bgschaid@jabber.org Tel: +43(3842)98282-42 Fax: >> +43(3842)98282-02 >> ---------------------------------------------------------------------------
>> _______________________________________________ CentOS mailing >> list CentOS@centos.org >> http://lists.centos.org/mailman/listinfo/centos
PK> _______________________________________________ CentOS mailing PK> list CentOS@centos.org PK> http://lists.centos.org/mailman/listinfo/centos
Bernhard Gschaider wrote on Wed, 19 Aug 2009 13:52:52 +0200:
- I always installed as a paravirtualized machine, Could it be that the install-kernel on the 5.3-media is not aware of this and somehow manages to shot the host
I haven't done completely new xen setups on 5.3 yet, only on earlier kernels and for these the answer is: no.
(because I noticed that most recipies on the net, including http://wiki.centos.org/HowTos/Xen/InstallingCentOSDomU never talk about paravirtualized (so I assume they use a fully virtualized guest)
Most of the recipes I know of either use virsh (which needs libvirt and is not xen-specific) or they advocate some oldish ways (like bootstrapping from a kernel outside of the VM) or are not aware of paravirtualization.
A "virt-install -p" (for paravirtualized) should get you going in an interactive fashion. If you have a kickstart file you can do a completely automated install with virt-install.
Kai
On 08/19/2009 12:52 PM, Bernhard Gschaider wrote:
- I always installed as a paravirtualized machine, Could it be that the install-kernel on the 5.3-media is not aware of this
the default install kernel is not used for the Xen install process, you want the stuff inside ~/images/xen/ for that.
-
Bernhard Gschaider -
Ian Murray -
Kai Schaetzl -
Karanbir Singh -
Marcelo M. Garcia -
Mathew S. McCarrell -
Pasi Kärkkäinen -
Ross Walker