Chris Andrews
2009-Sep-19 16:02 UTC
[Xen-users] which is the best way to setup DomU''s kernel location
Hello, I was wondering what do you guys thing is the best way to control the domU kernels. Would you A. use the name kernel for the all the domU''s using the dom0 kernel or B. make a boot partition inside the domU''s and use there own kernel? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Ady Deac
2009-Sep-20 08:58 UTC
Re: [Xen-users] which is the best way to setup DomU''s kernel location
Hi Chris, A: best if you could build a domU specific kernel. Try including everything in the kernel (ie. no modules). And include only the things you are sure you will need/use. B: then you will have to run domUs with the hardware virtualisation enabled and you will loose all the performance that Xen is offering in paravirtualised mode. Strongly consider the A option with custom domU. Have a directory in the root tree for those kernels. Worked best for me when migrating. Have phun! Chris Andrews wrote:> Hello, > > I was wondering what do you guys thing is the best way to control the > domU kernels. Would you A. use the name kernel for the all the domU''s > using the dom0 kernel or B. make a boot partition inside the domU''s and > use there own kernel? > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >-- Deac Mihai-Adrian W: www.mikesoftware.com P: +40-745-256.364 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Ian Murray
2009-Sep-20 09:18 UTC
[Xen-users] which is the best way to setup DomU''s kernel location
> A: best if you could build a domU specific kernel. Try including everything in> the kernel (ie. no modules). And include only the things you are sure you will> need/use. > > B: then you will have to run domUs with the hardware virtualisation enabledand> you will loose all the performance that Xen is offering in paravirtualisedmode.> > Strongly consider the A option with custom domU. Have a directory in the root > tree for those kernels. Worked best for me when migrating. > > Have phun! > > > Chris Andrews wrote: > > Hello, > > I was wondering what do you guys thing is the best way to control the > > domU kernels. Would you A. use the name kernel for the all the domU''s > > using the dom0 kernel or B. make a boot partition inside the domU''s and > > use there own kernel?You don''t need hardware-virtualisation to utilise the kernel that is stored inside the virtual machine. Just use pygrub or pvgrub. (last time I tried it the latter didn''t work with tap:aio, though) _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Ian Murray
2009-Sep-20 13:22 UTC
Re: [Xen-users] which is the best way to setup DomU''s kernel location
----- Original Message ----> From: Ady Deac <ady@mikesnet.ro> > To: Ian Murray <murrayie@yahoo.co.uk> > Sent: Sunday, 20 September, 2009 10:33:43 > Subject: Re: [Xen-users] which is the best way to setup DomU''s kernel location > > Hi Ian, > > Heh, you learn something new each day. ;) Thanks for the tip! > > Anyways, you still need to build the custom kernel. :P > > Have phun! >Hi, No you don''t. I am using pygrub with all my PV DomU''s, using the standard distribution kernels that come with CentOS 5.x in both Dom0 and DomU. Of pvGrub and pyGrub, I think pvgrub is the preferred option because of inherent security problems with pyGrub, but is available on newer hypervisors and not on the std CentOS hypervisor. I think the security issue goes along the lines of the DomU can affect something that runs on the Dom0 (pyGrub) by manipulating the grub menu in the DomU. This could be part of an attack, if some other vector is discovered in pygrub. Something like that, I think. I am sure some one will correct me, if I am wrong about that. HTH, Ian. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Ady Deac
2009-Sep-20 20:07 UTC
Re: [Xen-users] which is the best way to setup DomU''s kernel location
Hi Ian, I see you know all about running Xen kernels. You don''t even consider any advice from me at least. Then what is the purpose of your question? You asked for our opinions, but you consider yours to be the best. I''ve told you to build your own static domU kernels because in case you upgrade the dom0 kernel you need to update the domU''s modules as well. For 1-2 domU''s that''s fine, but do that for 2000-3000! Good luck with your strong beliefs! Ian Murray wrote:> > > ----- Original Message ---- > >> From: Ady Deac <ady@mikesnet.ro> >> To: Ian Murray <murrayie@yahoo.co.uk> >> Sent: Sunday, 20 September, 2009 10:33:43 >> Subject: Re: [Xen-users] which is the best way to setup DomU''s kernel location >> >> Hi Ian, >> >> Heh, you learn something new each day. ;) Thanks for the tip! >> >> Anyways, you still need to build the custom kernel. :P >> >> Have phun! >> >> > > Hi, > > No you don''t. I am using pygrub with all my PV DomU''s, using the > standard distribution kernels that come with CentOS 5.x in both Dom0 > and DomU. > > Of pvGrub and pyGrub, I think pvgrub is the preferred option because of inherent security problems with pyGrub, but is available on newer hypervisors and not on the std CentOS hypervisor. I think the security issue goes along the lines of the DomU can affect something that runs on the Dom0 (pyGrub) by manipulating the grub menu in the DomU. This could be part of an attack, if some other vector is discovered in pygrub. Something like that, I think. I am sure some one will correct me, if I am wrong about that. > > HTH, > > Ian. > > > > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >-- Deac Mihai-Adrian W: www.mikesoftware.com P: +40-745-256.364 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Ian Murray
2009-Sep-20 20:19 UTC
Re: [Xen-users] which is the best way to setup DomU''s kernel location
Erm, it wasn''t my question. You stated stated stuff as fact when it was your opinion. If you are running 2000 domu''s that may be the way to go (I presume you *are*?), but I have no experience of such. When do uphdrage your home rolled kernel, sounds like nightmare risk analysis. sorry fore top posting or whatever Yahoo mobile mail decides to do with this. On Sun, 20 Sep 2009 21:07 BST Ady Deac wrote:>Hi Ian, > >I see you know all about running Xen kernels. You don''t even consider >any advice from me at least. Then what is the purpose of your question? >You asked for our opinions, but you consider yours to be the best. > >I''ve told you to build your own static domU kernels because in case you >upgrade the dom0 kernel you need to update the domU''s modules as well. >For 1-2 domU''s that''s fine, but do that for 2000-3000! > > >Good luck with your strong beliefs! > > >Ian Murray wrote: >> >> >> ----- Original Message ---- >> >>> From: Ady Deac <ady@mikesnet.ro> >>> To: Ian Murray <murrayie@yahoo.co.uk> >>> Sent: Sunday, 20 September, 2009 10:33:43 >>> Subject: Re: [Xen-users] which is the best way to setup DomU''s kernel location >>> >>> Hi Ian, >>> >>> Heh, you learn something new each day. ;) Thanks for the tip! >>> >>> Anyways, you still need to build the custom kernel. :P >>> >>> Have phun! >>> >>> >> >> Hi, >> >> No you don''t. I am using pygrub with all my PV DomU''s, using the >> standard distribution kernels that come with CentOS 5.x in both Dom0 >> and DomU. >> >> Of pvGrub and pyGrub, I think pvgrub is the preferred option because of inherent security problems with pyGrub, but is available on newer hypervisors and not on the std CentOS hypervisor. I think the security issue goes along the lines of the DomU can affect something that runs on the Dom0 (pyGrub) by manipulating the grub menu in the DomU. This could be part of an attack, if some other vector is discovered in pygrub. Something like that, I think. I am sure some one will correct me, if I am wrong about that. >> >> HTH, >> >> Ian. >> >> >> >> >> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@lists.xensource.com >> http://lists.xensource.com/xen-users >> > >-- >Deac Mihai-Adrian > >W: www.mikesoftware.com >P: +40-745-256.364 >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users