Hello, On a DomU I''ve just replaced the Debian''s 2.6.26 kernel by a Vanilly 2.6.28.6 version (amd64). It seems to work very well (ext4 !), but should I reduce the size of the kernel ? For example, since the DomU use the "noop" scheduler, I can remove anticipatory, deadline, and cfq from my kernel, no ? And... is there any interest to do that ? Also the Dom0 use software raid and LVM, can I remove that support in DomU ? Thanks, Olivier B. PS : is it the good mailing list for that kind of question ? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Fri, Feb 20, 2009 at 11:02 PM, Olivier B. <xen.list@daevel.fr> wrote:> Hello, > > On a DomU I''ve just replaced the Debian''s 2.6.26 kernel by a Vanilly > 2.6.28.6 version (amd64). It seems to work very well (ext4 !), but should ICongratulations! Can you share your setup? It IS a pv domU, right? I tried 2.6.28.6 as domU kernel, and only able to get it working as 32bit PAE domU. 64bit domU doesn''t work. Can you share : - what Xen version you use and from where (debian or vanilla xen.org) - what is your domU kernel .config> reduce the size of the kernel ? > > For example, since the DomU use the "noop" scheduler, I can remove > anticipatory, deadline, and cfq from my kernel, no ? And... is there any > interest to do that ? > Also the Dom0 use software raid and LVM, can I remove that support in DomU ?Depends on what you''re trying to do. If you want it to be "easy", it should be as similar as possible as your domU distros'' vendor kernel. However if all your domU has the same kernel requirements (for example: all of them uses ext4 and none of them needs iptables) it might be beneficial to have a specialized kernel with all needed features built-in. Some "features" can be built as module anyway, so having them would allow - easy loading when needed - taking very little or no resource when not loaded As for LVM on domU, as of now it is the only way to be able to extend domU''s storage online (using xm block-attach and extending domU''s VG). If you don''t need to extend storage online (i.e. you can afford rebooting domU to add storage) then you can safely remove, but IMHO the space and memory savings will be somewhat insignificant. Regards, Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi, thanks ;) The host is an Intel Xeon X3350, running a Debian Lenny 64bits. I use on it the package "xen-hypervisor-3.2-1-amd64" from Debian and kernel "linux-image-2.6.26-1-xen-amd64" from Debian too. For the DomU, it was running the same Debian kernel, but I change it for a "home made" vanilla Kernel 2.6.28.6 (to can use the last version of ext4) : the config : http://apt.daevel.fr:9999/daevel/config-2.6.28.N-dae-xen the kernel : http://apt.daevel.fr:9999/daevel/linux-image-2.6.28.6-dae-xen_1.0_amd64.deb And the diff for .config with my "normal" kernel : daevel@may:~/linux$ diff config-2.6.28.N-dae-core2 config-2.6.28.N-dae-xen 160c160 < # CONFIG_FREEZER is not set --- > CONFIG_FREEZER=y 177c177,184 < # CONFIG_PARAVIRT_GUEST is not set --- > CONFIG_PARAVIRT_GUEST=y > CONFIG_XEN=y > CONFIG_XEN_MAX_DOMAIN_MEMORY=4 > CONFIG_XEN_SAVE_RESTORE=y > # CONFIG_KVM_CLOCK is not set > # CONFIG_KVM_GUEST is not set > CONFIG_PARAVIRT=y > CONFIG_PARAVIRT_CLOCK=y 294c301 < # CONFIG_HOTPLUG_CPU is not set --- > CONFIG_HOTPLUG_CPU=y 304a312,313 > CONFIG_PM_SLEEP_SMP=y > CONFIG_PM_SLEEP=y 317a327 > CONFIG_ACPI_HOTPLUG_CPU=y 329c339 < # CONFIG_ACPI_CONTAINER is not set --- > CONFIG_ACPI_CONTAINER=m 663a674 > CONFIG_XEN_BLKDEV_FRONTEND=y 1040a1052 > CONFIG_XEN_NETDEV_FRONTEND=y 1140a1153,1155 > CONFIG_HVC_DRIVER=y > CONFIG_HVC_IRQ=y > CONFIG_HVC_XEN=y 1482a1498,1499 > CONFIG_XEN_BALLOON=y > CONFIG_XEN_SCRUB_PAGES=y 1814c1831,1834 < # CONFIG_VIRTUALIZATION is not set --- > CONFIG_VIRTUALIZATION=y > # CONFIG_KVM is not set > # CONFIG_VIRTIO_PCI is not set > # CONFIG_VIRTIO_BALLOON is not set I hope this will help. Thanks for your advise. I want to limit "overhead" or "memory consuption" on DomU, but if I well understand you, there is not a big difference. So for simplicity I think I will add the required Xen options on my common kernel. For LVM, in fact I was not thinking we can use it directly from DomU ;) Thanks again, Olivier Fajar A. Nugraha a écrit :> On Fri, Feb 20, 2009 at 11:02 PM, Olivier B. <xen.list@daevel.fr> wrote: > >> Hello, >> >> On a DomU I''ve just replaced the Debian''s 2.6.26 kernel by a Vanilly >> 2.6.28.6 version (amd64). It seems to work very well (ext4 !), but should I >> > > Congratulations! > Can you share your setup? It IS a pv domU, right? > I tried 2.6.28.6 as domU kernel, and only able to get it working as > 32bit PAE domU. 64bit domU doesn''t work. Can you share : > - what Xen version you use and from where (debian or vanilla xen.org) > - what is your domU kernel .config > > >> reduce the size of the kernel ? >> >> For example, since the DomU use the "noop" scheduler, I can remove >> anticipatory, deadline, and cfq from my kernel, no ? And... is there any >> interest to do that ? >> Also the Dom0 use software raid and LVM, can I remove that support in DomU ? >> > > Depends on what you''re trying to do. If you want it to be "easy", it > should be as similar as possible as your domU distros'' vendor kernel. > However if all your domU has the same kernel requirements (for > example: all of them uses ext4 and none of them needs iptables) it > might be beneficial to have a specialized kernel with all needed > features built-in. > > Some "features" can be built as module anyway, so having them would allow > - easy loading when needed > - taking very little or no resource when not loaded > > As for LVM on domU, as of now it is the only way to be able to extend > domU''s storage online (using xm block-attach and extending domU''s VG). > If you don''t need to extend storage online (i.e. you can afford > rebooting domU to add storage) then you can safely remove, but IMHO > the space and memory savings will be somewhat insignificant. > > Regards, > > Fajar >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
But... I don''t see "vmx" in my /proc/cpuinfo :
flags : fpu de tsc msr pae cx8 apic sep mtrr cmov pat clflush
acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good pni
ssse3 cx16 sse4_1 lahf_lm
and :
root ! granite:~# xm dmesg | grep VMX
(XEN) CPU0: VMX disabled by BIOS.
(XEN) VMX: failed to initialise.
So VT is not used... maybe I should enable it ;)
Olivier
Olivier B. a écrit :> Hi,
>
> thanks ;) The host is an Intel Xeon X3350, running a Debian Lenny
> 64bits. I use on it the package "xen-hypervisor-3.2-1-amd64" from
> Debian and kernel "linux-image-2.6.26-1-xen-amd64" from Debian
too.
> For the DomU, it was running the same Debian kernel, but I change it
> for a "home made" vanilla Kernel 2.6.28.6 (to can use the last
version
> of ext4) :
> the config : http://apt.daevel.fr:9999/daevel/config-2.6.28.N-dae-xen
> the kernel :
> http://apt.daevel.fr:9999/daevel/linux-image-2.6.28.6-dae-xen_1.0_amd64.deb
>
>
> And the diff for .config with my "normal" kernel :
> daevel@may:~/linux$ diff config-2.6.28.N-dae-core2
> config-2.6.28.N-dae-xen
> 160c160
> < # CONFIG_FREEZER is not set
> ---
> > CONFIG_FREEZER=y
> 177c177,184
> < # CONFIG_PARAVIRT_GUEST is not set
> ---
> > CONFIG_PARAVIRT_GUEST=y
> > CONFIG_XEN=y
> > CONFIG_XEN_MAX_DOMAIN_MEMORY=4
> > CONFIG_XEN_SAVE_RESTORE=y
> > # CONFIG_KVM_CLOCK is not set
> > # CONFIG_KVM_GUEST is not set
> > CONFIG_PARAVIRT=y
> > CONFIG_PARAVIRT_CLOCK=y
> 294c301
> < # CONFIG_HOTPLUG_CPU is not set
> ---
> > CONFIG_HOTPLUG_CPU=y
> 304a312,313
> > CONFIG_PM_SLEEP_SMP=y
> > CONFIG_PM_SLEEP=y
> 317a327
> > CONFIG_ACPI_HOTPLUG_CPU=y
> 329c339
> < # CONFIG_ACPI_CONTAINER is not set
> ---
> > CONFIG_ACPI_CONTAINER=m
> 663a674
> > CONFIG_XEN_BLKDEV_FRONTEND=y
> 1040a1052
> > CONFIG_XEN_NETDEV_FRONTEND=y
> 1140a1153,1155
> > CONFIG_HVC_DRIVER=y
> > CONFIG_HVC_IRQ=y
> > CONFIG_HVC_XEN=y
> 1482a1498,1499
> > CONFIG_XEN_BALLOON=y
> > CONFIG_XEN_SCRUB_PAGES=y
> 1814c1831,1834
> < # CONFIG_VIRTUALIZATION is not set
> ---
> > CONFIG_VIRTUALIZATION=y
> > # CONFIG_KVM is not set
> > # CONFIG_VIRTIO_PCI is not set
> > # CONFIG_VIRTIO_BALLOON is not set
>
> I hope this will help.
>
> Thanks for your advise. I want to limit "overhead" or
"memory
> consuption" on DomU, but if I well understand you, there is not a big
> difference.
> So for simplicity I think I will add the required Xen options on my
> common kernel.
>
> For LVM, in fact I was not thinking we can use it directly from DomU ;)
>
> Thanks again,
> Olivier
>
> Fajar A. Nugraha a écrit :
>> On Fri, Feb 20, 2009 at 11:02 PM, Olivier B. <xen.list@daevel.fr>
wrote:
>>
>>> Hello,
>>>
>>> On a DomU I''ve just replaced the Debian''s 2.6.26
kernel by a Vanilly
>>> 2.6.28.6 version (amd64). It seems to work very well (ext4 !), but
>>> should I
>>>
>>
>> Congratulations!
>> Can you share your setup? It IS a pv domU, right?
>> I tried 2.6.28.6 as domU kernel, and only able to get it working as
>> 32bit PAE domU. 64bit domU doesn''t work. Can you share :
>> - what Xen version you use and from where (debian or vanilla xen.org)
>> - what is your domU kernel .config
>>
>>
>>> reduce the size of the kernel ?
>>>
>>> For example, since the DomU use the "noop" scheduler, I
can remove
>>> anticipatory, deadline, and cfq from my kernel, no ? And... is
there
>>> any
>>> interest to do that ?
>>> Also the Dom0 use software raid and LVM, can I remove that support
>>> in DomU ?
>>>
>>
>> Depends on what you''re trying to do. If you want it to be
"easy", it
>> should be as similar as possible as your domU distros'' vendor
kernel.
>> However if all your domU has the same kernel requirements (for
>> example: all of them uses ext4 and none of them needs iptables) it
>> might be beneficial to have a specialized kernel with all needed
>> features built-in.
>>
>> Some "features" can be built as module anyway, so having them
would
>> allow
>> - easy loading when needed
>> - taking very little or no resource when not loaded
>>
>> As for LVM on domU, as of now it is the only way to be able to extend
>> domU''s storage online (using xm block-attach and extending
domU''s VG).
>> If you don''t need to extend storage online (i.e. you can
afford
>> rebooting domU to add storage) then you can safely remove, but IMHO
>> the space and memory savings will be somewhat insignificant.
>>
>> Regards,
>>
>> Fajar
>>
>
>
> _______________________________________________
> 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 Sat, Feb 21, 2009 at 8:08 PM, Olivier B. <xen.list@daevel.fr> wrote:> But... I don''t see "vmx" in my /proc/cpuinfo : > > flags : fpu de tsc msr pae cx8 apic sep mtrr cmov pat clflush acpi > mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good pni ssse3 cx16 > sse4_1 lahf_lm > > and : > root ! granite:~# xm dmesg | grep VMX > (XEN) CPU0: VMX disabled by BIOS. > (XEN) VMX: failed to initialise. > > So VT is not used... maybe I should enable it ;)Don''t put much trust in /proc/cpuinfo on xen kernel. I think (on some versions) it actually HIDES vmx flag, for the obvious reason of not letting any userland programs use it. Here''s from my system flags : fpu de tsc msr pae cx8 apic sep mtrr cmov pat clflush acpi mmx fxsr sse sse2 ss ht syscall lm constant_tsc pni est cx16 lahf_lm yet # xm dmesg | grep VMX (XEN) HVM: VMX enabled Your xm dmesg output looks valid though, and you should enable it in BIOS. Regards, Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Sat, Feb 21, 2009 at 7:58 PM, Olivier B. <xen.list@daevel.fr> wrote:> thanks ;) The host is an Intel Xeon X3350, running a Debian Lenny 64bits. I > use on it the package "xen-hypervisor-3.2-1-amd64" from Debian and kernel > "linux-image-2.6.26-1-xen-amd64" from Debian too.> the config : http://apt.daevel.fr:9999/daevel/config-2.6.28.N-dae-xenHmmm ... there must be something in Xen 3.3.1 or my system that prevents 64bit vanilla domU kernel from working. I tried your .config on 2.6.28.6 and got the same result as my earlier tries. xm dmesg shows this: http://pastebin.com/f547d7bd1 What the heck is trap [#6] anyway? Thanks for sharing your setup though. Regards, Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users