Anyone using the IBM x445 machine as a xen host? Mike _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
So, there isn''t even one person using Xen on this hardware then? I''ve seen to many posts about this machine and Xen when I googled. If not Xen, is it compatible with any other Virtualization software then? On Thu, 15 May 2008 10:22:12 -0500, isplist@logicore.net wrote:> Anyone using the IBM x445 machine as a xen host? > > Mike > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
As a standalone (not running it in a clustered multi-chassis configuration) I can see no reason why it would not be xen compatible, it is simply a 2cpu Xeon box. If you are planning on clustering it, things may change and you would be best suited contacting an IBM rep. -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of isplist@logicore.net Sent: May 16, 2008 7:51 AM To: xen-users Subject: Re: [Xen-users] IBM x445, anyone using it? So, there isn''t even one person using Xen on this hardware then? I''ve seen to many posts about this machine and Xen when I googled. If not Xen, is it compatible with any other Virtualization software then? On Thu, 15 May 2008 10:22:12 -0500, isplist@logicore.net wrote:> Anyone using the IBM x445 machine as a xen host? > > Mike > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Fri, 16 May 2008 17:51:18 -0500, [STD]Ein wrote:> As a standalone (not running it in a clustered multi-chassis configuration) > I can see no reason why it would not be xen compatible, it is simply a 2cpu > Xeon box. If you are planning on clustering it, things may change and you > would be best suited contacting an IBM rep.The machines I have are all 8-way XEON''s. I do not have any clustered or extended to 16-way. Someone was telling me in another thread that these machines are not, might not, be Xen compatible machines.> Nothing to change (in BIOS). You''re gonna need much newer hardware if you want > HVM. The x445 is pretty old and the processors and BIOS on those > systems do not support hardware virtualization.I do have VirtMan running, it see''s dom0, 16 VCPU''s, 8GB memory. However, when I try to install a guest, I am not getting anywhere. I copied a distro to a location on the xen host. I went through the new virtual server configuration. The default install path is; /var/lib/xen/images/mynewinstall.img When I try to install, I keep getting; Invalid install location I thought I had the right hardware but the Fully Virtualized option isn''t available, it''s grayed out. Mike> -----Original Message----- > From: xen-users-bounces@lists.xensource.com > [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of > isplist@logicore.net > Sent: May 16, 2008 7:51 AM > To: xen-users > Subject: Re: [Xen-users] IBM x445, anyone using it? > > So, there isn''t even one person using Xen on this hardware then? > I''ve seen to many posts about this machine and Xen when I googled. > > If not Xen, is it compatible with any other Virtualization software then? > > > On Thu, 15 May 2008 10:22:12 -0500, isplist@logicore.net wrote: >> Anyone using the IBM x445 machine as a xen host? >> >> Mike >> >> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@lists.xensource.com >> http://lists.xensource.com/xen-users > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Fri, May 16, 2008 at 7:18 PM, isplist@logicore.net <isplist@logicore.net> wrote:> The machines I have are all 8-way XEON''s. I do not have any clustered or extended to 16-way. > Someone was telling me in another thread that these machines are not, might not, be Xen compatible machines.Yep. The max for a single node x445 is 8 processors, no dual core support that I am aware of. To get 16 procs, you need to take two of them, cable them and then it MAY work, or it may not. To be honest, I never had the hardware to try, and the idea was kind of scary. The multi-noding seems to work far better in the newer IBM systesm like x3950 and x3950-M2. I never tested Xen on them either. They were End of Lifed before Xen showed up in RHEL and SLES. Also, to the best of my recollection, they were 32bit only boxes. And, as I said before, there is no hardware virutalization support on those processors or BIOS.>> Nothing to change (in BIOS). You''re gonna need much newer hardware if you want >> HVM. The x445 is pretty old and the processors and BIOS on those >> systems do not support hardware virtualization. > > I do have VirtMan running, it see''s dom0, 16 VCPU''s, 8GB memory. > However, when I try to install a guest, I am not getting anywhere.Have you tried installing from scratch, using virt-manager (in RHEL/Fedora) or using YaST (in SLES/SuSE)? Just from the little bit you have shared, your problem has NOTHING to do with hardware virtualization, unless you are trying to take a HVM guest from one Xen box that supports VT, and trying to run it on a different Xen box that does NOT support VT. Sounds more like a filesystem issue or something like that. Really, use virt-manager or YaST and install a paravirtualized guest just to see if it works. Besides, you have a running system, and a running Dom0, so Xen works. Dom0 is, in reality, just a paravirtualized guest OS running on the hypervisor.> > I copied a distro to a location on the xen host. > I went through the new virtual server configuration. > The default install path is; /var/lib/xen/images/mynewinstall.img > When I try to install, I keep getting; Invalid install locationWhat does this mean? You copied a working guest filesystem image to your new Xen box, or you copied an install tree? What OS are you using for the Host? What OS are you using for the guest? How is your install tree set up (file tree, ISO, or what?)> I thought I had the right hardware but the Fully Virtualized option isn''t available, it''s grayed out.Again, as I said before, you will not have Fully Virtualized abilities on the x445, it does not support the hardware virtualization code, and I am almost sure that it won''t even support the processors that have HVM code on them (Though that is just a guess, so YMMV there). And to answer your other questions... virtualbox may work, but it''s rather new, and I''ve never tried it myself. VMWare MAY work, especially as the older VMWare versions (Server and ESX) are 32 bit RHEL based and do not AFAIK require VT code on the processors, it works just fine on non-vt boxes here. But again, you have Xen booted, and a running Dom0, so Xen is doing what it''s supposed to do... my money is on a bad install tree (which is what that error you shared seems to point to) or trying to run a full virt guest from one Xen box on a second Xen box that does not support full virt. Good Luck, Jeff _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> Yep. The max for a single node x445 is 8 processors, no dual core > support that I am aware of.What type of processors should I be looking for which are properly supported then?> showed up in RHEL and SLES. Also, to the best of my recollection, > they were 32bit only boxes. And, as I said before, there is no > hardware virutalization support on those processors or BIOS.Yes, 32bit.> Just from the little bit you have shared, your problem has NOTHING to > do with hardware virtualization, unless you are trying to take a HVM > guest from one Xen box that supports VT, and trying to run it on a > different Xen box that does NOT support VT.It''s just a fresh CentOS install with Virtualization because I wanted to try out Xen.> Sounds more like a filesystem issue or something like that.I''m not sure that there is a problem, perhaps a little configuration which is not installed by default or such?> Really, use virt-manager or YaST and install a paravirtualized guest > just to see if it works. Besides, you have a running system, and a > running Dom0, so Xen works. Dom0 is, in reality, just a > paravirtualized guest OS running on the hypervisor.That''s exactly what I''ve tried and received the path error :). Using Virtual Machine Manager, I''ve tried to install a pre-configured ISO. It was simply what I had handy. I can try something else. Is there something I can try from the command line? I just want a basic Linux install, no servers, nothing for now.> What does this mean? You copied a working guest filesystem image to > your new Xen box, or you copied an install tree? What OS are you > using for the Host? What OS are you using for the guest? How is your > install tree set up (file tree, ISO, or what?)It''s an ISO of a pre-installed CentOS OS with qmail pre-configured along with other tools. Just had it handy when I first gave this a quick try.> Again, as I said before, you will not have Fully Virtualized abilities > on the x445, it does not support the hardware virtualization code, and > I am almost sure that it won''t even support the processors that have > HVM code on them (Though that is just a guess, so YMMV there).That''s fine, like I too said, I just happen to have these machines sitting here so was hoping I might be able to use them with Xen. From what I can tell, I won''t be needing fully virtualized machines anyhow. I don''t tend to consolidate things which I try to get the most power from. In other words, I won''t be virtualizing machines which need to be as powerful as they can be. I will be virtualizing machines which don''t do a lot, DNS servers for example are pretty simple I/O machines, very low use web, mail, other servers, things like that.> And to answer your other questions... virtualbox may work, but it''s > rather new, and I''ve never tried it myself. VMWare MAY work,I didn''t ask about this but I think it''s in the thread somewhere. Either way, if I can use the x445 for non fully virtualized machines, that still would be cool. It would allow me to shut down a couple dozen low use boxes, virtualizing them along with their storage on SAN.> But again, you have Xen booted, and a running Dom0, so Xen is doing > what it''s supposed to do... my money is on a bad install tree (which > is what that error you shared seems to point to) or trying to run a > full virt guest from one Xen box on a second Xen box that does not > support full virt.I''ll look around for a guest which is known to easily work para-virtualized. If you know of one, please let me know in the meantime. Thanks. Mike _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > Just from the little bit you have shared, your problem has NOTHING to > > do with hardware virtualization, unless you are trying to take a HVM > > guest from one Xen box that supports VT, and trying to run it on a > > different Xen box that does NOT support VT. > > It''s just a fresh CentOS install with Virtualization because I wanted to > try out Xen. > > > Sounds more like a filesystem issue or something like that. > > I''m not sure that there is a problem, perhaps a little configuration which > is not installed by default or such? > > > Really, use virt-manager or YaST and install a paravirtualized guest > > just to see if it works. Besides, you have a running system, and a > > running Dom0, so Xen works. Dom0 is, in reality, just a > > paravirtualized guest OS running on the hypervisor. > > That''s exactly what I''ve tried and received the path error :). > Using Virtual Machine Manager, I''ve tried to install a pre-configured ISO. > It was simply what I had handy. I can try something else. Is there > something I can try from the command line? I just want a basic Linux > install, no servers, nothing for now. > > > What does this mean? You copied a working guest filesystem image to > > your new Xen box, or you copied an install tree? What OS are you > > using for the Host? What OS are you using for the guest? How is your > > install tree set up (file tree, ISO, or what?) > > It''s an ISO of a pre-installed CentOS OS with qmail pre-configured along > with other tools. Just had it handy when I first gave this a quick try.ISO usually refers to an image of a DVD/CD-ROM but it sounds like you''re talking about an image of a hard drive, am I right? Or are you using a custom CD-ROM or something like that? You can''t install a paravirtualised guest from a disk, it needs to be a net install, with you supplying a location of an online (possibly a local mirror) RPM repository. Alternatively if you''re copying existing hard drive images directly into /var/lib/xen/images and then trying to boot them, I suppose there could be some kind of SELinux labelling issue going on here...> I didn''t ask about this but I think it''s in the thread somewhere. Either > way, if I can use the x445 for non fully virtualized machines, that still > would be cool. It would allow me to shut down a couple dozen low use boxes, > virtualizing them along with their storage on SAN.You should be able to run PV domains on them without too much bother. As Jeff notes, if dom0 is booted successfully everything *should* work OK once the setup issues are resolved. Since your hardware *definitely* should support PV guests OK based on what we''ve seen, I think we need to go back-to-basics a bit in debugging this. In addition to my questions above, it would be helpful to have a more specific idea of the steps you have taken during the attempted installation of this guest, so that we can see what went wrong and how.> I''ll look around for a guest which is known to easily work > para-virtualized. If you know of one, please let me know in the meantime. > Thanks.CentOS > 4.5 should work OK as a PV guest, as should Fedora releases for the past few years. You ought to be able to network install them in virt-manager fairly straightforwardly once we''ve figured out what your current problem is. Cheers, Mark -- Push Me Pull You - Distributed SCM tool (http://www.cl.cam.ac.uk/~maw48/pmpu/) _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Mon, May 19, 2008 at 2:15 PM, isplist@logicore.net <isplist@logicore.net> wrote:> What type of processors should I be looking for which are properly supported then?If you want to run full virtualization, any of the newer dual/quad core Intel and AMD chips support virtualization. For intel, this should include the latest Xeons, Core 2 chips and others.. not sure about Celerons though. For AMD, the newer AMD64 chips do, both dual and quad core, and maybe some of the newest single core chips too, but I am not positive on actual model names/numbers... at least, I don''t have a list of names/models handy.> It''s just a fresh CentOS install with Virtualization because I wanted to try out Xen.Like I said, you have Domain 0 running, so Xen is doing its thing... dom0 is just a paravirtualized guest to begin with.> I''m not sure that there is a problem, perhaps a little configuration which is not installed by default or such?Maybe... I''ve never used CentOS, but I''ve done hundreds of RHEL Xen installs and have yet to run into issues like what you''re seeing, and since CentOS is mostly rebadged RHEL, the differences should be minimal between the two...>> Really, use virt-manager or YaST and install a paravirtualized guest >> just to see if it works. Besides, you have a running system, and a >> running Dom0, so Xen works. Dom0 is, in reality, just a >> paravirtualized guest OS running on the hypervisor. > > That''s exactly what I''ve tried and received the path error :). > Using Virtual Machine Manager, I''ve tried to install a pre-configured ISO. It was simply what I had handy. I can try something else. Is there > something I can try from the command line? I just want a basic Linux install, no servers, nothing for now.I think that may be the key there... you''re using a preconfigured ISO? I assume this means a preinstalled Guest image? To be honest, I''ve tried several flavors of those and never gotten one to boot. What I was suggesting, and for paravirt you''ll have to do it this way: build an NFS mountable (or http mountable) install tree using the CentOS install media, NOT the preconfigured thing you''re using now. Then use Virt-manager to create a new guest from scratch. Tell it you need to install an OS (YaST asks this, can''t remember of virt-manager does or not) and for installation source, use the nfs or http URL for your install tree. For example.... I have two servers. S1 is a NFS/HTTP server that hosts installation trees built from DVDs (I just copy the DVD contents from INSTALLATION DVDs into a directory like /install/distro-name. S2 is a Xen host that I want to install a guest on. So, on S2, launch virt-manager. Connect to the hypervisor and click NEW. Give the guest a name. Choose Paravirtualized (that should be your only option on this box) On the Install media line on the next screen, enter http://ip.of.server./path/to/installtion/tree In my case, the install media line looks like this: http://172.0.0.253/install/RHEL5.2/ which points to a full install tree for RHEL 5.2. Select simple file on next screen and make it at least 6 - 8 GB (I''ve found that the 4GB default is not usually big enough once you add in swap) Be sure the "Allocate entire virtual disk now" option is checked. I''m not a fan of sparse files... better IMO to have the full filesystem allocated than not have room later... Choose your network settings as appropriate for your environment Choose memor and VCPUs as appropriate. Also note, I normally make guests with a minimum of 1024M RAM... but I have memory to spare. Now, provided that your install tree is created correctly and is network accessible, you should be ready to go. Clicking finish on the last screen will start the guest and being the install process. You can also put a file tree on your local machine... If you do that, though, I think you may still have to have nfs or apache running to make it available, because what you are basically doing is a network install of the OS onto the new guest.> It''s an ISO of a pre-installed CentOS OS with qmail pre-configured along with other tools. Just had it handy when I first gave this a quick try.Thanks for pointing that out. I was confused. See above. Like I said, I''ve never really had much luck with preconfigured Xen guests. I HAVE run preconfigured guests in VMWare before, but the Xen ones always seem to fail for one reason or another... but I don''t remember ever seeing the error you were seeing, but now that I understand what you are trying to do, let me correct that to say that I dont remember seeing it, meaning I may well have seen it and just didn''t recall...> That''s fine, like I too said, I just happen to have these machines sitting here so was hoping I might be able to use them with Xen. From what I can > tell, I won''t be needing fully virtualized machines anyhow. I don''t tend to consolidate things which I try to get the most power from. In other words, > I won''t be virtualizing machines which need to be as powerful as they can be. I will be virtualizing machines which don''t do a lot, DNS servers for > example are pretty simple I/O machines, very low use web, mail, other servers, things like that.Honestly, I do all this in a test environment... I beta test Linux for a living, so I dont get the chance to use this stuff in the "real world" like a lot of you do. The upside is that I have done this a LOT, the downside, is that my installations never live longer than a week before they are flattened and rebuilt. That being said, for what you want to do, If at all possible, I would move to a 64bit machine and run 64bit Xen, using 64bit and 32 bit guests. Using a 32bit Xen machine limits you to the 32bit memory limits and prevents a lot of expansion. 64bit systesm let you use a LOT more ram and gives you the benefit of being able to run both 64 and 32 bit guests on your host system. Also, I wouldn''t worry too much about hardware virtualization unless you discover a REAL need for it (like running unmodified Windows guests, etc) because HVM guests tend to be a lot slower than paravirt guests, in my experience. (and for you Xen gurus out there, no, I don''t do any real bench marking... this is more of a seat of the pants kind of experience...) Hope that helps... Jeff _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Simple enough to give this a try, or, not really :). I recently worked on consolidating a bunch of storage which included a new NFS server for access to my distros for network installs. Having to finish this leads me to a dozen other things which need to get done, which leads to a number of... it just goes on. I''ll get back to this as soon as I get a handle on the work I had started earlier. While searching on why I can''t seem to get ServeRAID 4Mx controllers working all of a sudden, I came across an article on IBM''s site that VMWare runs on the even older x440. Does that mean that Xen is the culprit, not being very compatible with older gear or something else? Mike On Mon, 19 May 2008 19:42:03 +0100, Mark Williamson wrote:>>> Just from the little bit you have shared, your problem has NOTHING to >>> >>> do with hardware virtualization, unless you are trying to take a HVM >>> guest from one Xen box that supports VT, and trying to run it on a >>> different Xen box that does NOT support VT. >>> >> It''s just a fresh CentOS install with Virtualization because I wanted to >> try out Xen. >> >>> Sounds more like a filesystem issue or something like that. >>> >> I''m not sure that there is a problem, perhaps a little configuration which >> is not installed by default or such? >> >>> Really, use virt-manager or YaST and install a paravirtualized guest >>> just to see if it works. Besides, you have a running system, and a >>> running Dom0, so Xen works. Dom0 is, in reality, just a >>> paravirtualized guest OS running on the hypervisor. >>> >> That''s exactly what I''ve tried and received the path error :). >> Using Virtual Machine Manager, I''ve tried to install a pre-configured ISO. >> It was simply what I had handy. I can try something else. Is there >> something I can try from the command line? I just want a basic Linux >> install, no servers, nothing for now. >> >>> What does this mean? You copied a working guest filesystem image to >>> your new Xen box, or you copied an install tree? What OS are you >>> using for the Host? What OS are you using for the guest? How is your >>> install tree set up (file tree, ISO, or what?) >>> >> It''s an ISO of a pre-installed CentOS OS with qmail pre-configured along >> with other tools. Just had it handy when I first gave this a quick try. >> > ISO usually refers to an image of a DVD/CD-ROM but it sounds like you''re > talking about an image of a hard drive, am I right? Or are you using a > custom CD-ROM or something like that? > > You can''t install a paravirtualised guest from a disk, it needs to be a net > install, with you supplying a location of an online (possibly a local > mirror) > RPM repository. > > Alternatively if you''re copying existing hard drive images directly > into /var/lib/xen/images and then trying to boot them, I suppose there could > be some kind of SELinux labelling issue going on here... > >> I didn''t ask about this but I think it''s in the thread somewhere. Either >> way, if I can use the x445 for non fully virtualized machines, that still >> would be cool. It would allow me to shut down a couple dozen low use >> boxes, >> virtualizing them along with their storage on SAN. >> > You should be able to run PV domains on them without too much bother. As > Jeff > notes, if dom0 is booted successfully everything *should* work OK once the > setup issues are resolved. > > Since your hardware *definitely* should support PV guests OK based on what > we''ve seen, I think we need to go back-to-basics a bit in debugging this. > In > addition to my questions above, it would be helpful to have a more specific > idea of the steps you have taken during the attempted installation of this > guest, so that we can see what went wrong and how. > >> I''ll look around for a guest which is known to easily work >> para-virtualized. If you know of one, please let me know in the meantime. >> Thanks. >> > CentOS > 4.5 should work OK as a PV guest, as should Fedora releases for the > past few years. You ought to be able to network install them in virt- > manager > fairly straightforwardly once we''ve figured out what your current problem > is. > > Cheers, > Mark_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Tue, May 20, 2008 at 2:06 PM, isplist@logicore.net <isplist@logicore.net> wrote:> While searching on why I can''t seem to get ServeRAID 4Mx controllers working all of a sudden, I came across an article on IBM''s site that VMWare runs on the even older x440. > > Does that mean that Xen is the culprit, not being very compatible with older gear or something else?Not necessarily... it''s all a matter of limitations. You''ll find that VMware on those boxen is, like Xen, limited to 32 bit OSs and all the physical limitations of hte 32 bit architecture... the versions of VMware that we tested on 440s, 445s and that generation of System X machines was based on RHEL 2.1 and RHEL 3. So you''re limited by the limitations of the underlying OS... Xen, on the other hand, works rather well with RHEL 5 and SLES 10, and I''ve heard, though not tried this myself, RHEL 4 and SLES 9. heck, I''m running it right now on an old single core box w/ RHEL 5.1 and 16GB ram for my own development purposes... _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > While searching on why I can''t seem to get ServeRAID 4Mx controllers > > working all of a sudden, I came across an article on IBM''s site that > > VMWare runs on the even older x440. > > > > Does that mean that Xen is the culprit, not being very compatible with > > older gear or something else? > > Not necessarily... it''s all a matter of limitations. You''ll find that > VMware on those boxen is, like Xen, limited to 32 bit OSs and all the > physical limitations of hte 32 bit architecture... the versions of > VMware that we tested on 440s, 445s and that generation of System X > machines was based on RHEL 2.1 and RHEL 3. So you''re limited by the > limitations of the underlying OS...Nb VMware would give you full virtualisation support on your pre-HVM hardware, which Xen can''t give you.> Xen, on the other hand, works rather well with RHEL 5 and SLES 10, and > I''ve heard, though not tried this myself, RHEL 4 and SLES 9. > > heck, I''m running it right now on an old single core box w/ RHEL 5.1 > and 16GB ram for my own development purposes...I suggest you try a "vanilla" virt-manager install of a non-preconfigured guest, as Jeff described in his previous e-mail. As he observed, since dom0 is apparently booting OK on your machine, your hardware is basically 100% certain to be able to support Xen domUs as well. If dom0 boots, paravirt domUs should *always* boot. What you''re running into is most to be a weird CentOS / virt-manager behaviour rather than a true Xen problem or a hardware-specific problem. Cheers, Mark -- Push Me Pull You - Distributed SCM tool (http://www.cl.cam.ac.uk/~maw48/pmpu/) _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Tue, May 20, 2008 at 3:04 PM, Mark Williamson <mark.williamson@cl.cam.ac.uk> wrote:> Nb VMware would give you full virtualisation support on your pre-HVM hardware, > which Xen can''t give you.Good point... but isn''t there really a difference between say, full HVM virtualization on Xen and VMWare which is more emulation in this case? That''s just for curiosity sake...>> Xen, on the other hand, works rather well with RHEL 5 and SLES 10, and >> I''ve heard, though not tried this myself, RHEL 4 and SLES 9. >> > What you''re running into is most to be a weird CentOS / virt-manager behaviour > rather than a true Xen problem or a hardware-specific problem.I think it has to do with those pre-configured images that you can download via the internet. I''ve never had luck getting them to work correctly, and it usually has something to do with the filesystem. I''ve had no real problem, for instance, building a fresh domU on RHEL/Xen, then tarring that up and saving it to deploy on another RHEL/Xen box, but as far as using one of the pre-made CentOS/Fedora/Slackware/distroOfchoice images, I''ve had no luck at all. Granted, I only run the Xen versions that ship with RHEL and SuSE, so I dont do a lot with other Xen versions... -- ------------------> Jeffrey Lane - W4KDH <------------------- www.jefflane.org Another cog in the great Corporate Wheel The internet has no government, no constitution, no laws, no rights, no police, no courts. Don''t talk about fairness or innocence, and don''t talk about what should be done. Instead, talk about what is being done and what will be done by the amorphous unreachable undefinable blob called "the internet user base." -Paul Vixie _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Tue, May 20, 2008 at 2:11 PM, Jeff Lane <sundowner225@gmail.com> wrote:> On Tue, May 20, 2008 at 3:04 PM, Mark Williamson > <mark.williamson@cl.cam.ac.uk> wrote: > >> Nb VMware would give you full virtualisation support on your pre-HVM hardware, >> which Xen can''t give you. > > Good point... but isn''t there really a difference between say, full > HVM virtualization on Xen and VMWare which is more emulation in this > case? That''s just for curiosity sake...VMWare does emulation for the ''hard'' parts, where the existing 386-era virtualization doesn''t cut it. it''s heavily optimized, and does a lot of code-modification on the fly to get it to manageable levels. HVM-capable hardware makes it a lot easier, but (the first generation, at least) incurs in heavy switching costs, so it''s not a ''day and night'' performance advantage. it''s most a ''any hardware/complex code'' vs. ''new hardware/simpler code'' tradeoff. and, of course, VMWare is starting to use HVM capabilities for some hard cases, and Xen/KVM are getting more PV into HVM... -- Javier _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> <mark.williamson@cl.cam.ac.uk> wrote: > > Nb VMware would give you full virtualisation support on your pre-HVM > > hardware, which Xen can''t give you. > > Good point... but isn''t there really a difference between say, full > HVM virtualization on Xen and VMWare which is more emulation in this > case? That''s just for curiosity sake...Well, interesting question... It''s implemented differently but in terms of guest behaviour I don''t think you''ll notice any difference in real use. Technically hardware support virtualisation might be more complete but VMware have, at this point, had many years to get really good at doing convincing full virtualisation in software. They actually recompile guest machine code at runtime in order to reduce emulation overheads, whilst hiding this from the guest. VMware is quite highly optimised to run guests efficiently without hardware support. ISTR them saying when HVM hardware first came out that they''d benchmarked and found their software-only solution was faster than their HVM-based solution, so they were sticking with the software solution for the time being. That doesn''t tell you much about the performance of HVM-vs-software solutions in general, though, and both the hardware and the software has moved on since then. What it does tell you is that that HVM isn''t automatically "better" than a pure software solution, although it is likely to leave the latter behind as time progresses. Using VMware to do full virtualisation on old non-HVM hardware is not going to be especially fast but it may well be quite usable. Equally well, using Xen to run supported PV guests is likely to yield much better performance on the same hardware, if you have the option of running supported guests in the first place (i.e. don''t want Windows etc).> >> Xen, on the other hand, works rather well with RHEL 5 and SLES 10, and > >> I''ve heard, though not tried this myself, RHEL 4 and SLES 9. > > > > What you''re running into is most to be a weird CentOS / virt-manager > > behaviour rather than a true Xen problem or a hardware-specific problem. > > I think it has to do with those pre-configured images that you can > download via the internet. I''ve never had luck getting them to work > correctly, and it usually has something to do with the filesystem. > I''ve had no real problem, for instance, building a fresh domU on > RHEL/Xen, then tarring that up and saving it to deploy on another > RHEL/Xen box, but as far as using one of the pre-made > CentOS/Fedora/Slackware/distroOfchoice images, I''ve had no luck at > all. > > Granted, I only run the Xen versions that ship with RHEL and SuSE, so > I dont do a lot with other Xen versions...I''ve had great success with letting virt-manager do a network install of PV CentOS/Fedora guests over HTTP from an RPM repository somewhere. I think I''ve done it both by serving a local RPM repository using Apache and by connecting to public mirror sites. Works great for me and is so convenient I''ve never felt the need to use preconfigured images. I do sometimes clone my own images in order to save the install time, though. Cheers, Mark -- Push Me Pull You - Distributed SCM tool (http://www.cl.cam.ac.uk/~maw48/pmpu/) _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users