Re: [Xen-users] pv_ops Dom0 kernel for DomU?

[Pasi Kärkkäinen <pasik@xxxxxx>]

On Mon, May 17, 2010 at 08:54:35AM +0100, Ian Tobin wrote:
> Hi,
> 
> How do you gernerate it from DomU when it wont boot?
> 

Well.. mount + chroot + mkinitrd from dom0 might work.

I prefer installing domUs using the distro installer so things
like this get handled automatically. 

And I prefer using Xen pygrub so I don't have to have the kernel+initrd in dom0 
at all!

> Here is the domU config
> 
> CONFIG_XEN=y
> CONFIG_XEN_MAX_DOMAIN_MEMORY=32
> CONFIG_XEN_SAVE_RESTORE=y
> CONFIG_XEN_DEBUG_FS=y
> CONFIG_XEN_BLKDEV_FRONTEND=y
>

So the xen-blkfront is compiled in, you don't necessarily need an initrd then.


> CONFIG_NETXEN_NIC=m
> CONFIG_XEN_NETDEV_FRONTEND=y
> CONFIG_XEN_KBDDEV_FRONTEND=y
> CONFIG_HVC_XEN=y
> CONFIG_XEN_FBDEV_FRONTEND=y
> CONFIG_XEN_BALLOON=y
> CONFIG_XEN_SCRUB_PAGES=y
> CONFIG_XEN_DEV_EVTCHN=y
> CONFIG_XENFS=y
> CONFIG_XEN_COMPAT_XENFS=y
> CONFIG_XEN_SYS_HYPERVISOR=y
> 

-- Pasi

> Thanks
> 
> Ian
> 
> 
> 
> -----Original Message-----
> From: Pasi Kärkkäinen [mailto:pasik@xxxxxx] 
> Sent: 17 May 2010 08:51
> To: Ian Tobin
> Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [Xen-users] pv_ops Dom0 kernel for DomU?
> 
> On Mon, May 17, 2010 at 08:40:34AM +0100, Ian Tobin wrote:
> > Hey Pasi,
> > 
> > Ive downloaded 2.6.33.4 from kernel.org.  The XEN stuff is compiled as 
> > static and so is raid,i have created a initrd image by issueing the 
> > following (Debian OS)
> > 
> > Mkinitramfs -o /boot/initrd.img-2.6.33.4 2.6.33.4    
> > 
> 
> Did you generate the initrd in dom0? You should generate it in domU.. 
> then you won't have all the dom0-specific md-raid stuff etc there.
> 
> > When booting i get the same error
> > 
> > 
> > Loading, please wait...
> > Begin: Loading essential drivers ... done.
> > Begin: Running /scripts/init-premount ... FATAL: Error inserting fan 
> > (/lib/modules/2.6.33.4/kernel/drivers/acpi/fan.ko): No such device
> > FATAL: Error inserting thermal 
> > (/lib/modules/2.6.33.4/kernel/drivers/acpi/thermal.ko): No such device
> > done.
> > Begin: Mounting root file system ... Begin: Running /scripts/local-top ... 
> > Begin: LoadingFailure: failed to load module raid1.
> > done.
> > Begin: Assembling all MD arrays ... [    1.991528] md: md0 stopped.
> > mdadm: no devices found for /dev/md0
> > [    2.004392] md: md1 stopped.
> > mdadm: no devices found for /dev/md1
> > [    2.021788] md: md2 stopped.
> > mdadm: no devices found for /dev/md2
> > [    2.047173] md: md3 stopped.
> > mdadm: no devices found for /dev/md3
> > Failure: failed to assemble all arrays.
> > done.
> > Begin: Waiting for udev to process events ... done.
> > done.
> > Begin: Waiting for root file system ...
> > 
> > 
> > Im not sure if i have missed something out, any ideas?
> > 
> 
> Please paste "grep XEN .config" from the domU kernel.
> 
> -- Pasi
> 
> 
> 
> > Cheers
> > 
> > Ian
> > 
> > 
> > -----Original Message-----
> > From: Pasi Kärkkäinen [mailto:pasik@xxxxxx] 
> > Sent: 14 May 2010 21:18
> > To: Ian Tobin
> > Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> > Subject: Re: [Xen-users] pv_ops Dom0 kernel for DomU?
> > 
> > On Fri, May 14, 2010 at 09:05:02PM +0100, Ian Tobin wrote:
> > > Oh right, thats new to me. Ive never had to do that before, is that new 
> > > to the pv_ops?
> > > 
> > 
> > It's not really pvops specific.. it's more about the fact that nowadays 
> > all/most
> > drivers are built as modules - so you need to have an initrd image to load 
> > them.
> > 
> > If you compiled all the xen* stuff as static/built-in then you wouldn't 
> > need an initrd..
> > 
> > > Many thanks for the info, you learn something new everyday :)
> > > 
> > 
> > Np.
> > 
> > -- Pasi
> > 
> > > Ian
> > > 
> > > 
> > > -----Original Message-----
> > > From: Pasi Kärkkäinen [mailto:pasik@xxxxxx] 
> > > Sent: 14 May 2010 20:50
> > > To: Ian Tobin
> > > Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> > > Subject: Re: [Xen-users] pv_ops Dom0 kernel for DomU?
> > > 
> > > On Fri, May 14, 2010 at 08:45:03PM +0100, Ian Tobin wrote:
> > > > Ah ok, what would be the procedure to do that? 
> > > > 
> > > > Thanks
> > > > 
> > > 
> > > Usually it's best to generate the initrd image in the guest,
> > > and use the distro provided domU kernel.
> > > 
> > > If you install the guest using the guest distro installer it'll do it for 
> > > you automatically.
> > > 
> > > You can also do it from dom0.. example for centos/rhel/fedora:
> > > 
> > > mkinitrd -v -f --with-module=xenblk --with-module=xennet 
> > > /boot/initrd-domU-version.img <kernelversion>
> > > 
> > > -- Pasi
> > > 
> > > > Ian
> > > > 
> > > > 
> > > > 
> > > > -----Original Message-----
> > > > From: Pasi Kärkkäinen [mailto:pasik@xxxxxx] 
> > > > Sent: 14 May 2010 20:32
> > > > To: Ian Tobin
> > > > Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> > > > Subject: Re: [Xen-users] pv_ops Dom0 kernel for DomU?
> > > > 
> > > > On Fri, May 14, 2010 at 08:27:50PM +0100, Ian Tobin wrote:
> > > > > Ok strange. I have set the DomU config to use the kernel i use for 
> > > > > Dom0 and when booting it gets so far to mount the root filesystem and 
> > > > > then complains that it cant load the raid1 module which then says it 
> > > > > can't load md0, md1, md2 and md3 which are my Dom0 software raid 
> > > > > disks.
> > > > > 
> > > > > When i use the 2.6.8.18 kernel the domU boots fine.
> > > > > 
> > > > > I have in the config to use the initrd.img-2.6.32.12 ram disk but it 
> > > > > doesn't work, am i missing something obvious?
> > > > > 
> > > > 
> > > > Are you using the dom0 initrd for domU? 
> > > > If you are, you shouldn't.
> > > > 
> > > > domU needs to have its own initrd that loads drivers for the virtual 
> > > > hardware the Xen guest has..
> > > > 
> > > > -- Pasi
> > > > 
> > > > > Thanks
> > > > > 
> > > > > Ian
> > > > > 
> > > > > 
> > > > > -----Original Message-----
> > > > > From: Pasi Kärkkäinen [mailto:pasik@xxxxxx] 
> > > > > Sent: 14 May 2010 19:48
> > > > > To: Ian Tobin
> > > > > Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> > > > > Subject: Re: [Xen-users] pv_ops Dom0 kernel for DomU?
> > > > > 
> > > > > On Fri, May 14, 2010 at 03:08:57PM +0100, Ian Tobin wrote:
> > > > > >    Hi,
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > >    Just wondered if we can use the pv_ops kernel in Jermeys tree 
> > > > > > for linux PV
> > > > > >    domU or do we need to get that one from kernel.org ?
> > > > > > 
> > > > > 
> > > > > Both will work.
> > > > > 
> > > > > upstream kernel.org kernels do have basic Xen PV domU support 
> > > > > out-of-the-box.
> > > > > Jeremy's tree has some additional features, like pcifront/pciback etc,
> > > > > that are not yet upstream.
> > > > > 
> > > > > -- Pasi
> > > > > 
> > > > > > 
> > > > > > 
> > > > > >    Thanks
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > >    Ian
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > 
> > > > > > _______________________________________________
> > > > > > Xen-users mailing list
> > > > > > Xen-users@xxxxxxxxxxxxxxxxxxx
> > > > > > http://lists.xensource.com/xen-users
> > > > > 
> > > > > 
> > > > 
> > > > 
> > > 
> > > 
> > 
> > 
> 
> 

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