Hello, I run xen 3.0.3 on Debian 4.0 and so far I''ve got 5 guests. I''ve read in the user documentation that it''s better to use blktap than loopback, because of performance reasons, so i decided to switch to it. However, the root device isn''t found by the guest system. I read something about CONFIG_XEN_BLKDEV_TAP being needed in the kernel for it to work, is that true? I have CONFIG_XEN_BLKDEV_BACKEND=y # CONFIG_XEN_BLKDEV_TAP is not set CONFIG_XEN_BLKDEV_FRONTEND=y The guest config disk line looks like this: disk = [ ''tap:aio:/var/xen/domains/ac/disk.img,sda1,w'', ''tap:aio:/var/xen/domains/ac/swap.img,sda2,w'' ] /Jonathan _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Sat, Apr 14, 2007 at 11:54:06PM +0200, Jonathan Selander wrote:> Hello, > > I run xen 3.0.3 on Debian 4.0 and so far I''ve got 5 guests. I''ve read in > the user documentation that it''s better to use blktap than loopback, > because of performance reasons, so i decided to switch to it. However, > the root device isn''t found by the guest system. I read something about > CONFIG_XEN_BLKDEV_TAP being needed in the kernel for it to work, is that > true? I have > > CONFIG_XEN_BLKDEV_BACKEND=y > # CONFIG_XEN_BLKDEV_TAP is not set > CONFIG_XEN_BLKDEV_FRONTEND=yYeah, I believe it should be set to CONFIG_XEN_BLKDEV_TAP=m If it was working, you''d also get a ''blktapctrl'' daemon spawned by Xen. If you look at syslog you''ll probably find blktapctrl trying to start and failing to initialize if blktap support was missing in kernel.> The guest config disk line looks like this: > > disk = [ ''tap:aio:/var/xen/domains/ac/disk.img,sda1,w'', > ''tap:aio:/var/xen/domains/ac/swap.img,sda2,w'' ]That''s the correct config file syntax. Dan. -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=| _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
after changing your kernel config CONFIG_XEN_BLKDEV_TAP=m config should be disk = [ ''tap:aio:/var/xen/domains/ac/disk.img,xvda1,w'', ''tap:aio:/var/xen/domains/ac/swap.img,xvda2,w'' ] update your fstab of domU too. for me works fine with this config. -------------------- Itamar Reis Peixoto e-mail: itamar@ispbrasil.com.br msn: itamarjp@starmedia.com skype: itamarjp icq: 81053601 +55 34 3238 3845 +55 11 4063 5033 ----- Original Message ----- From: "Daniel P. Berrange" <berrange@redhat.com> To: "Jonathan Selander" <jonathan@spinea.se> Cc: <xen-users@lists.xensource.com> Sent: Saturday, April 14, 2007 8:35 PM Subject: Re: [Xen-users] blktap on debian> On Sat, Apr 14, 2007 at 11:54:06PM +0200, Jonathan Selander wrote: >> Hello, >> >> I run xen 3.0.3 on Debian 4.0 and so far I''ve got 5 guests. I''ve read in >> the user documentation that it''s better to use blktap than loopback, >> because of performance reasons, so i decided to switch to it. However, >> the root device isn''t found by the guest system. I read something about >> CONFIG_XEN_BLKDEV_TAP being needed in the kernel for it to work, is that >> true? I have >> >> CONFIG_XEN_BLKDEV_BACKEND=y >> # CONFIG_XEN_BLKDEV_TAP is not set >> CONFIG_XEN_BLKDEV_FRONTEND=y > > Yeah, I believe it should be set to > > CONFIG_XEN_BLKDEV_TAP=m > > If it was working, you''d also get a ''blktapctrl'' daemon spawned by Xen. If > you look at syslog you''ll probably find blktapctrl trying to start and > failing to initialize if blktap support was missing in kernel. > >> The guest config disk line looks like this: >> >> disk = [ ''tap:aio:/var/xen/domains/ac/disk.img,sda1,w'', >> ''tap:aio:/var/xen/domains/ac/swap.img,sda2,w'' ] > > That''s the correct config file syntax. > > Dan. > -- > |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 > 2496 -=| > |=- Perl modules: > .cpan.org/~danberr/ -=| > |=- Projects: > at.net/~danielpb/ -=| > |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B > 505 -=| > > _______________________________________________ > 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
Nb. just to clarify, you do not need the blktap module in the domU kernel. From the guest''s PoV there''s no difference. Cheers, Mark On Saturday 14 April 2007 23:46, Itamar Reis Peixoto wrote:> after changing your kernel config > > CONFIG_XEN_BLKDEV_TAP=m > > config should be > > disk = [ ''tap:aio:/var/xen/domains/ac/disk.img,xvda1,w'', > ''tap:aio:/var/xen/domains/ac/swap.img,xvda2,w'' ] > > update your fstab of domU too. > > for me works fine with this config. > > -------------------- > > Itamar Reis Peixoto > > e-mail: itamar@ispbrasil.com.br > msn: itamarjp@starmedia.com > skype: itamarjp > icq: 81053601 > +55 34 3238 3845 > +55 11 4063 5033 > ----- Original Message ----- > From: "Daniel P. Berrange" <berrange@redhat.com> > To: "Jonathan Selander" <jonathan@spinea.se> > Cc: <xen-users@lists.xensource.com> > Sent: Saturday, April 14, 2007 8:35 PM > Subject: Re: [Xen-users] blktap on debian > > > On Sat, Apr 14, 2007 at 11:54:06PM +0200, Jonathan Selander wrote: > >> Hello, > >> > >> I run xen 3.0.3 on Debian 4.0 and so far I''ve got 5 guests. I''ve read in > >> the user documentation that it''s better to use blktap than loopback, > >> because of performance reasons, so i decided to switch to it. However, > >> the root device isn''t found by the guest system. I read something about > >> CONFIG_XEN_BLKDEV_TAP being needed in the kernel for it to work, is that > >> true? I have > >> > >> CONFIG_XEN_BLKDEV_BACKEND=y > >> # CONFIG_XEN_BLKDEV_TAP is not set > >> CONFIG_XEN_BLKDEV_FRONTEND=y > > > > Yeah, I believe it should be set to > > > > CONFIG_XEN_BLKDEV_TAP=m > > > > If it was working, you''d also get a ''blktapctrl'' daemon spawned by Xen. > > If you look at syslog you''ll probably find blktapctrl trying to start and > > failing to initialize if blktap support was missing in kernel. > > > >> The guest config disk line looks like this: > >> > >> disk = [ ''tap:aio:/var/xen/domains/ac/disk.img,sda1,w'', > >> ''tap:aio:/var/xen/domains/ac/swap.img,sda2,w'' ] > > > > That''s the correct config file syntax. > > > > Dan. > > -- > > > > |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 > > > > 2496 -=| > > > > |=- Perl modules: > > > > .cpan.org/~danberr/ -=| > > > > |=- Projects: > > > > at.net/~danielpb/ -=| > > > > |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B > > > > 505 -=| > > > > _______________________________________________ > > 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-- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users