Hi, I have a naive question. People can RTFM me if they point me to an appropriate manual. I have a 64 bit x86_64 machine running a 32 bit Dom0. I want to install a 32 bit DomU on top of it doing direct network access. 1. My first question is xm create requires a DomU kernel. Where do I get one such kernel from? 2. I have a single network NIC, will I need separate NICs if I want to do direct NIC access from DomU? Also, any specific differences in xm create if I want to do direct device access. Answers to either of the query will greatly help! Regards, Asim _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Asim schrieb:> Hi, > > I have a naive question. People can RTFM me if they point me to an > appropriate manual. > > I have a 64 bit x86_64 machine running a 32 bit Dom0. I want to > install a 32 bit DomU on top of it doing direct network access.What is 64 bit then???? when your base system and your guest is 32 bit? Nothing is bothered that your cpu could understand also 64bit binaries.> > 1. My first question is xm create requires a DomU kernel. Where do I > get one such kernel from?just a 2.624 or 2.625 linux kernel will do this job for 32bit if configured correctly (look in menuconfig for xen supprt).> > 2. I have a single network NIC, will I need separate NICs if I want to > do direct NIC access from DomU? Also, any specific differences > in xm create if I want to do direct device access.xen normally bridges all the network stuff together, so you gets some kind of a nice virtual switch where all is connected. regards, florian> > Answers to either of the query will greatly help! > > Regards, > Asim > > _______________________________________________ > 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
1) xm create requires a domU file that specifies a kernel. You get the kernel from a kernel package - usually they''re labeled with and -xen version. I highly recommend, though, that you use something like virt-manager and/or vm-install to install domUs, generate configs, etc. It makes life a lot easier when dealing with Xen domUs. You can find virt-manager at http://virt-manager.et.redhat.com. As far as 32-bit vs. 64-bit, the vm-install tools will automatically choose for you based on the install media you have available. If you have install media that supports both 32 and 64 bit, 64 bit is usually the default. If you have a 32-bit only install media, the tools are able to work with that. Please note that most 64-bit versions of Xen I''ve used require that anything 32-bit use PAE, unless you''re doing HVM, in which case you can use just about whatever you like. 2) You don''t want to do direct NIC access to a domU, you want to use a bridge. By default XEN creates a bridge (can''t remember what they''re calling it these days) that bridges eth0 to all of your domUs. This should allow you to use your single network card with as many domUs as you have on your system. -Nick>>> On Thu, Apr 24, 2008 at 1:19 PM, Asim <linkasim@gmail.com> wrote:Hi, I have a naive question. People can RTFM me if they point me to an appropriate manual. I have a 64 bit x86_64 machine running a 32 bit Dom0. I want to install a 32 bit DomU on top of it doing direct network access. 1. My first question is xm create requires a DomU kernel. Where do I get one such kernel from? 2. I have a single network NIC, will I need separate NICs if I want to do direct NIC access from DomU? Also, any specific differences in xm create if I want to do direct device access. Answers to either of the query will greatly help! Regards, Asim This e-mail may contain confidential and privileged material for the sole use of the intended recipient. If this email is not intended for you, or you are not responsible for the delivery of this message to the intended recipient, please note that this message may contain SEAKR Engineering (SEAKR) Privileged/Proprietary Information. In such a case, you are strictly prohibited from downloading, photocopying, distributing or otherwise using this message, its contents or attachments in any way. If you have received this message in error, please notify us immediately by replying to this e-mail and delete the message from your mailbox. Information contained in this message that does not relate to the business of SEAKR is neither endorsed by nor attributable to SEAKR. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> 2) You don''t want to do direct NIC access to a domU, you want to use a > bridge. By default XEN creates a bridge (can''t remember what they''re > calling it these days) that bridges eth0 to all of your domUs. This should > allow you to use your single network card with as many domUs as you have on > your system. > >I want to do passthrough I/O for my specific needs and not use virbr0. I believe this will also disable migration if am not wrong? So, to do a direct NIC access I think I should hide this PCI from Domain-0, so will need a second additional NIC? -Asim _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
What is your reason for wanting to do passthrough I/O? The only really good reason I can think of for it is that you have an application that requires very high throughput and extremely low latency. Otherwise the bridge should be fine, and I can think of several reasons why you don''t want to use passthrough I/O. One of which is the one you mentioned - migration will be worthless because your domUs will be hardware dependent. So, if you''re still insistent upon doing passthrough I/O, then, yes, you''ll need one network card for every domU you have running. -Nick>>> On Thu, Apr 24, 2008 at 2:39 PM, Asim <linkasim@gmail.com> wrote:> 2) You don''t want to do direct NIC access to a domU, you want to use a > bridge. By default XEN creates a bridge (can''t remember what they''re > calling it these days) that bridges eth0 to all of your domUs. This should > allow you to use your single network card with as many domUs as you have on > your system. > >I want to do passthrough I/O for my specific needs and not use virbr0. I believe this will also disable migration if am not wrong? So, to do a direct NIC access I think I should hide this PCI from Domain-0, so will need a second additional NIC? -Asim This e-mail may contain confidential and privileged material for the sole use of the intended recipient. If this email is not intended for you, or you are not responsible for the delivery of this message to the intended recipient, please note that this message may contain SEAKR Engineering (SEAKR) Privileged/Proprietary Information. In such a case, you are strictly prohibited from downloading, photocopying, distributing or otherwise using this message, its contents or attachments in any way. If you have received this message in error, please notify us immediately by replying to this e-mail and delete the message from your mailbox. Information contained in this message that does not relate to the business of SEAKR is neither endorsed by nor attributable to SEAKR. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thanks Nick for all the information. Yes I want to do some performance measurements on pass-through I/O (and bridge I/O). So I just want one DomU. I guess thats two NICs one for each Dom*. Apart from lack of migration support, what are the other disadvantages? Also, how do i do this? Do i need to hide the PCI from Dom0 and add it using network-attach script? -Asim On Thu, Apr 24, 2008 at 3:50 PM, Nick Couchman <Nick.Couchman@seakr.com> wrote:> > > What is your reason for wanting to do passthrough I/O? The only really good > reason I can think of for it is that you have an application that requires > very high throughput and extremely low latency. Otherwise the bridge should > be fine, and I can think of several reasons why you don''t want to use > passthrough I/O. One of which is the one you mentioned - migration will be > worthless because your domUs will be hardware dependent. > > > So, if you''re still insistent upon doing passthrough I/O, then, yes, you''ll > need one network card for every domU you have running. > > > -Nick > > > > >>> On Thu, Apr 24, 2008 at 2:39 PM, Asim <linkasim@gmail.com> wrote: > > > > > > > > 2) You don''t want to do direct NIC access to a domU, you want to use a > > bridge. By default XEN creates a bridge (can''t remember what they''re > > calling it these days) that bridges eth0 to all of your domUs. This > should > > allow you to use your single network card with as many domUs as you have > on > > your system. > > > > > > I want to do passthrough I/O for my specific needs and not use virbr0. > I believe > this will also disable migration if am not wrong? So, to do a direct NIC > access > I think I should hide this PCI from Domain-0, so will need a second > additional > NIC? > > -Asim > > > > ________________________________ > This e-mail may contain confidential and privileged material for the sole > use of the intended recipient. If this email is not intended for you, or you > are not responsible for the delivery of this message to the intended > recipient, please note that this message may contain SEAKR Engineering > (SEAKR) Privileged/Proprietary Information. In such a case, you are strictly > prohibited from downloading, photocopying, distributing or otherwise using > this message, its contents or attachments in any way. If you have received > this message in error, please notify us immediately by replying to this > e-mail and delete the message from your mailbox. Information contained in > this message that does not relate to the business of SEAKR is neither > endorsed by nor attributable to SEAKR. > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Mainly I''m thinking of expandability - passing through your NICs to your domU directly means that each NIC can only be connected to one domU - and ease of configuration - passing through NICs means messing around with PCI settings, matching the right PCI bus identifier to the right NIC port, etc. If you''re testing performance of passthrough vs. bridge, I can see why you''d want to do that. I''ve got three servers set up to run a bunch of domUs (I have probably 30 running on 3 physical servers right now) and I need VLAN support plus network aggregation. All of this is easier to do in the dom0 and create a bunch of bridges that the domUs can connect to. Very similar to the way VMware''s ESX does things. My servers are also 1U servers, so I don''t have a lot of room to expand PCIe cards or anything like that - I have to make the most of the small amount of space given. -Nick>>> On 2008/04/24 at 16:54, Asim <linkasim@gmail.com> wrote:Thanks Nick for all the information. Yes I want to do some performance measurements on pass-through I/O (and bridge I/O). So I just want one DomU. I guess thats two NICs one for each Dom*. Apart from lack of migration support, what are the other disadvantages? Also, how do i do this? Do i need to hide the PCI from Dom0 and add it using network-attach script? -Asim On Thu, Apr 24, 2008 at 3:50 PM, Nick Couchman <Nick.Couchman@seakr.com> wrote:> > > What is your reason for wanting to do passthrough I/O? The only really good > reason I can think of for it is that you have an application that requires > very high throughput and extremely low latency. Otherwise the bridge should > be fine, and I can think of several reasons why you don''t want to use > passthrough I/O. One of which is the one you mentioned - migration will be > worthless because your domUs will be hardware dependent. > > > So, if you''re still insistent upon doing passthrough I/O, then, yes, you''ll > need one network card for every domU you have running. > > > -Nick > > > > >>> On Thu, Apr 24, 2008 at 2:39 PM, Asim <linkasim@gmail.com> wrote: > > > > > > > > 2) You don''t want to do direct NIC access to a domU, you want to use a > > bridge. By default XEN creates a bridge (can''t remember what they''re > > calling it these days) that bridges eth0 to all of your domUs. This > should > > allow you to use your single network card with as many domUs as you have > on > > your system. > > > > > > I want to do passthrough I/O for my specific needs and not use virbr0. > I believe > this will also disable migration if am not wrong? So, to do a direct NIC > access > I think I should hide this PCI from Domain-0, so will need a second > additional > NIC? > > -Asim > > > > ________________________________ > This e-mail may contain confidential and privileged material for the sole > use of the intended recipient. If this email is not intended for you, or you > are not responsible for the delivery of this message to the intended > recipient, please note that this message may contain SEAKR Engineering > (SEAKR) Privileged/Proprietary Information. In such a case, you are strictly > prohibited from downloading, photocopying, distributing or otherwise using > this message, its contents or attachments in any way. If you have received > this message in error, please notify us immediately by replying to this > e-mail and delete the message from your mailbox. Information contained in > this message that does not relate to the business of SEAKR is neither > endorsed by nor attributable to SEAKR. > >This e-mail may contain confidential and privileged material for the sole use of the intended recipient. If this email is not intended for you, or you are not responsible for the delivery of this message to the intended recipient, please note that this message may contain SEAKR Engineering (SEAKR) Privileged/Proprietary Information. In such a case, you are strictly prohibited from downloading, photocopying, distributing or otherwise using this message, its contents or attachments in any way. If you have received this message in error, please notify us immediately by replying to this e-mail and delete the message from your mailbox. Information contained in this message that does not relate to the business of SEAKR is neither endorsed by nor attributable to SEAKR. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users