Xen users - Nov 2012 - FW: RE: How to change VM from para-virtualization to full-virtualization?

Forwarding to Alexandre....

Regards,
Jerry
ECN: (887) 17175
Phone: +86 10 6439 4175

This Communication is Confidential. We only send and receive email on the basis
of the terms set out at
www.ericsson.com/email_disclaimer<http://www.ericsson.com/email_disclaimer>


______________________________________________
From:   Jing Chen
Sent:   Thursday, November 08, 2012 2:14 PM
To:     xen-users-bounces@lists.xen.org
Cc:     Jerry Gao
Subject:        RE: [Xen-users] How to change VM from para-virtualization      
to      full-virtualization?

Hello Alexandre.
     This is Jing and I work with Jerry for this issue. I saw your email and do
some test following your instruction. As our case, I met lots of issues since
there are lots of track as you said. I list them here and need your help to
check.
Seems it is a little bit longger. But your help is grateful.

I create a PV for DomU and install the SUSE linux 11 SP2. my configurations are
as below.

1) partition.


2) /etc/fstab file


3) /boot/grub/menu.lst

    in PV, grub has been installed. The option 0 is the one work normally in PV.
I add the second option for HVM.
4) the conf file in Dom0 is as below.


To chagne PV to HVM. I do the following modification.
5) change conf file in Dom0


6) change /etc/fstab as below

7) change /etc/mtab as below


Then. I start up the HVM using xm create command. And the error is as below.


  I try to change root parameter in menu.lst, such as
"root=/dev/hda2". But it still can not startup saying can not mount
/dev/hda2 to root.

Please give your advise what can I do.

Thanks very much.

Jing Chen

CBC/XIB/K
No.5 Lize East Street, Chaoyang District
100102, Beijing, China
Phone +86 10 84767586
Mobile +86 13801223973
jing.chen@ericsson.com
www.ericsson.com




This Communication is Confidential. We only send and receive email on the basis
of the terms set out at www.ericsson.com/email_disclaimer

-----Original Message-----
From: Jerry Gao
Sent: Monday, November 05, 2012 4:28 PM
To: Jing Chen
Subject: FW: [Xen-users] How to change VM from para-virtualization to
full-virtualization?




Regards,
Jerry
ECN: (887) 17175
Phone: +86 10 6439 4175

This Communication is Confidential. We only send and receive email on the basis
of the terms set out at www.ericsson.com/email_disclaimer

-----Original Message-----
From: xen-users-bounces@lists.xen.org [mailto:xen-users-bounces@lists.xen.org]
On Behalf Of Alexandre Kouznetsov
Sent: Friday, November 02, 2012 1:22 AM
To: xen-users@lists.xen.org
Subject: Re: [Xen-users] How to change VM from para-virtualization to
full-virtualization?

Hello.

El 31/10/12 18:54, Jerry Gao escribió:
> "3. Re-write your .cfg file within Dom0 to make it start the DomU as
HVM."
> Which .cfg file are you referring to? Is there an example of it? Thanks.
HVM and PV guests needs different options in the config file. They share some
basic variables, such as "name", "memory", etc, but, for
example, "root" option has nothing to do in a config for HVM, and
"builder" is not suitable for PV mode.

The PV configs I use are generated by Debian''s xen-tools, and my HVM
regular config has been copied from one place to another multiple times with
minor changes, since I build it years ago.
As command reference, i have used this link back then:
http://wiki.prgmr.com/mediawiki/index.php/Appendix_B:_The_Structure_of_the_Xen_Config_File

A quick look around suggests this link as a good start to create own''s
HVM config:
http://www.virtuatopia.com/index.php/Configuring_and_Installating_a_Xen_Hardware_Virtual_Machine_%28HVM%29_domainU_Guest
(it is one of many, pick whatever you like)
> About the 4th step:
> "4. Install the boot loader into you DomU storage''s MBR,
watch the kernel command line for root= parameter. I would recommend doing this
booting the HVM DomU with a LiveCD, Knoppix or systemrescuecd should do
fine."
> Are you talking about to change the menu.list file of grub? Would you
please help to give me more details about this step.
A common PV DomU have no grub or menu.lst at all. The bootloader''s
function (obtain and execute kernel, unpack initrd in DomU''s memory) is
handled by the hypervisor and controlled from scripts within Dom0. In some cases
it''s desirable to allow DomU to control what kernel it shall boot, so a
special tool "pygrub" is used: it is executed in Dom0, finds the
DomU''s disk image and extracts from it a minimalistic menu.lst file.
That menu.lst mentions a kernel and initrd images that are usually stored in the
same disk image, so pygrub extracts them as well. If that is your case, you
already have a menu.lst but need to make it usable by a normal Grub.

Recently I had to do something similar, I has do change the paths to the kernel
and initrd files, and add parameters "root=/dev/hda2 ro" to the kernel
line. Note that menu.lst config is used by legacy Grub, while
Grub2 (most commonly encountered this days) uses a completely different format
and config filename.

In case of HVM, the boot loading process is more "normal", compared to
a bare metal computer. Treat it as any other grub-enabled system. In case of
Debian[-based] you might just use update-grub script and it will generate a nice
config for you.
I mention Grub because it is the most common. Strictly speaking, lilo or
syslinux would work well here as well, but you will find less reference about
them, specially related to Xen.
> About the 5th step:
> "5. Modify your /etc/fstab to reflect the change of the block devices
naming (from /dev/xvdaN to /dev/hda or whatever)."
> My previous VM is created on a virtual hard disk like /dev/drbd00. Then do
I still need to change the storage device name?
Definitely yes.
Even if you pass /dev/drbd00 as is to HVM DomU, it will see it as /dev/hda or
whatever you specified in your config file. Boot your DomU with a LiveCD and
verify the correct device names.

Also take in account that the common baremetal installations does not put a FS
directly on a block device. The block device are partitioned first. For sake of
simplicity, Xen PV use to put FS directly on the
device: for example, /dev/xvda1 is not the first partition of xvda, instead
it''s whole device named xvda1, which shares nothing with xvda2.
If you use this approach within a HVM, you might confuse it, because it will
expect to access FS on partitioned devices.

Another trick is, that legacy Grub can''t read ext4 filesystem. Even
better, it can''t read ext3 filesystem if formatted with inode size of
256 bytes, which is the default for a modern mkfs.ext3. In my case, i had to use
"mkfs.ext -I 128" in order to make it work with legacy Grub.
Grub2 does not have this problem.

> -----Original Message-----
> From: xen-users-bounces@lists.xen.org
> [mailto:xen-users-bounces@lists.xen.org] On Behalf Of Alexandre
> Kouznetsov
> Sent: Wednesday, October 31, 2012 1:30 PM
> To: xen-users@lists.xen.org
> Subject: Re: [Xen-users] How to change VM from para-virtualization to
full-virtualization?
>
> Hi.
>
> El 31/10/12 10:27, Jerry Gao escribió:
>> I''ve created a domU in para-virtualization. But now I need to
change
>> it to full-virtualization.
>> Is it possible to upgrade/change the VM virtualization mode without
>> impact the OS+App in the VM? And How?
>
> Yes, it is possible. Can be a bit tricky because there are many details to
take care of, even if each of this details is trivial by itself.
>   From DomU''s point of view, the change will affect the kernel
used in the DomU, the boot loader and the storage devices naming.
>
> This is a small overview of what need to be done:
> 1. Make sure your DomU system has a regular kernel and a boot loader
installed.
> 2. Make sure the storage is presented to the DomU as a partitioned block
device(s).
> 3. Re-write your .cfg file within Dom0 to make it start the DomU as HVM.
> 4. Install the boot loader into you DomU storage''s MBR, watch the
kernel command line for root= parameter. I would recommend doing this booting
the HVM DomU with a LiveCD, Knoppix or systemrescuecd should do fine.
> 5. Modify your /etc/fstab to reflect the change of the block devices naming
(from /dev/xvdaN to /dev/hda or whatever).
>
> Word of advice, in many cases it''s preferable to re-install the
guest system, then move data and configs. This way you get a more predictable
result.
>
> --
> Alexandre Kouznetsov
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xen.org
> http://lists.xen.org/xen-users
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xen.org
> http://lists.xen.org/xen-users
>

--
Alexandre Kouznetsov


_______________________________________________
Xen-users mailing list
Xen-users@lists.xen.org
http://lists.xen.org/xen-users











_______________________________________________
Xen-users mailing list
Xen-users@lists.xen.org
http://lists.xen.org/xen-users

Hello.

It''s something wrong with your e-mail formatting, the screenshots you 
attached are not displayed inline.

Please consider not using HTML formatting when sending mails to the 
list. If you wish to share the output you get from your system, post or 
attach it as plain text.

El 08/11/12 01:53, Jerry Gao escribió:
> *From: *Jing Chen
> *Sent: *Thursday, November 08, 2012 2:14 PM
>       This is Jing and I work with Jerry for this issue. I saw your
> email and do some test following your instruction. As our case, I met
> lots of issues since there are lots of track as you said. I list them
> here and need your help to check.
> Seems it is a little bit longger. But your help is grateful.
> I create a PV for DomU and install the SUSE linux 11 SP2. my
> configurations are as below.
> 1) partition.
I guess this is the screenshot showing "expert partitioner". As I 
understand it, this is how your PV guest looks initially and you use 
/dev/xvda2 as LVM physical volume. /dev/xvda2 seems to be a true 
partition within /dev/xvda, to you already have a partitioned block 
device for you HVM.
> 2) /etc/fstab file
Looks fine to me. Since your guest uses LVM, the device names are 
expected to remain unchanged after you switch to HVM, except /dev/xvda1 
for /boot.
> 3) /boot/grub/menu.lst
>      in PV, grub has been installed. The option 0 is the one work
> normally in PV. I add the second option for HVM.
Note, that since your /boot is on separated partition, the path to 
kernel and initrd are wrong. As you specify it, they would be searched 
under /boot/boot.
Remove the "/boot" prefix from pathnames of kernel and initrd images, 
your files are on "root" of your /boot partition.
> 4) the conf file in Dom0 is as below.
As I see, your DomU''s xvda resides on your Dom0''s /dev/sda4.
This is not
something I would recommend becouse of risk of confusion, one between 
many others). But should work if you are careful enough.

As a note, personally I use LVM within Dom0 (not DomU) and export 
multiple logical volumes as the DomU needs them. This instead of 
exporting a single block device and manage it''s volumes within DomU.
> To chagne PV to HVM. I do the following modification.
> 5) change conf file in Dom0
boot="d" should make you boot from CDROM, I''m not sure if
that''s your
intention.
In any case, it''s good idea to boot a liveCD first, specially to take a
look how the storage is presented to the DomU and make sure the boot 
loader is correctly installed.

So, does it boots from ISO?
> 6) change /etc/fstab as below
Looks good, but will work only if your LVM infrastructure is correctly 
recognized.
> 7) change /etc/mtab as below
/etc/mtab is usually auto-generated, in rare cases it needs to be 
modified by hand. In some occasion I had to do it to trick grub 
installer to place it''s code in the correct place.
> Then. I start up the HVM using xm create command. And the error is as
below.
>    I try to change root parameter in menu.lst, such as
"root=/dev/hda2".
> But it still can not startup saying can not mount /dev/hda2 to root.
Actually, it complains about mounting /dev/vg69/root. Not /dev/hda2, 
which is your physical volume, not root filesystem. (Am I looking to a 
wrong place?)

You have a rather complex storage setup. One of the benefits of 
virtualization is that you can hide this complexity from the VM, keeping 
it very simple, very small, very stable. Caesar''s to Caesar, and 
infrastructure management to Dom0.

In this case, I bet initrd does not have LVM support, that''s why it 
can''t see /dev/vg69/root. Please consult your distribution 
documentation, about how to re-build initrd. Surely it''s a very 
automated process.
> Please give your advise what can I do.
Consider this steps:
1. Boot using the VM using your distribution''s live CD in some
"rescue"
mode.
2. Make sure your /dev/hda, and all it''s partitions and logical volumes
are readable and mountable.
3. Threat this case as a normal, not virtualized machine that got 
something wrong with it''s booting. Suse documentation shall cover it.


-- 
Alexandre Kouznetsov

Hello, Jing.

(Sorry if this is repeated. I don''t see this mail I sent since
yesterday
in the list, so I re-send it.)

It''s something wrong with your e-mail formatting, the screenshots you 
attached are not displayed inline.

Please consider not using HTML formatting when sending mails to the 
list. If you wish to share the output you get from your system, post or 
attach it as plain text.

El 08/11/12 01:53, Jerry Gao escribió:
> *From: *Jing Chen
> *Sent: *Thursday, November 08, 2012 2:14 PM
>       This is Jing and I work with Jerry for this issue. I saw your
> email and do some test following your instruction. As our case, I met
> lots of issues since there are lots of track as you said. I list them
> here and need your help to check.
> Seems it is a little bit longger. But your help is grateful.
> I create a PV for DomU and install the SUSE linux 11 SP2. my
> configurations are as below.
> 1) partition.
I guess this is the screenshot showing "expert partitioner". As I 
understand it, this is how your PV guest looks initially and you use 
/dev/xvda2 as LVM physical volume. /dev/xvda2 seems to be a true 
partition within /dev/xvda, to you already have a partitioned block 
device for you HVM.
> 2) /etc/fstab file
Looks fine to me. Since your guest uses LVM, the device names are 
expected to remain unchanged after you switch to HVM, except /dev/xvda1 
for /boot.
> 3) /boot/grub/menu.lst
>      in PV, grub has been installed. The option 0 is the one work
> normally in PV. I add the second option for HVM.
Note, that since your /boot is on separated partition, the path to 
kernel and initrd are wrong. As you specify it, they would be searched 
under /boot/boot.
Remove the "/boot" prefix from pathnames of kernel and initrd images, 
your files are on "root" of your /boot partition.
> 4) the conf file in Dom0 is as below.
As I see, your DomU''s xvda resides on your Dom0''s /dev/sda4.
This is not
something I would recommend becouse of risk of confusion, one between 
many others). But should work if you are careful enough.

As a note, personally I use LVM within Dom0 (not DomU) and export 
multiple logical volumes as the DomU needs them. This instead of 
exporting a single block device and manage it''s volumes within DomU.
> To chagne PV to HVM. I do the following modification.
> 5) change conf file in Dom0
boot="d" should make you boot from CDROM, I''m not sure if
that''s your
intention.
In any case, it''s good idea to boot a liveCD first, specially to take a
look how the storage is presented to the DomU and make sure the boot 
loader is correctly installed.

So, does it boots from ISO?
> 6) change /etc/fstab as below
Looks good, but will work only if your LVM infrastructure is correctly 
recognized.
> 7) change /etc/mtab as below
/etc/mtab is usually auto-generated, in rare cases it needs to be 
modified by hand. In some occasion I had to do it to trick grub 
installer to place it''s code in the correct place.
> Then. I start up the HVM using xm create command. And the error is as
below.
>    I try to change root parameter in menu.lst, such as
"root=/dev/hda2".
> But it still can not startup saying can not mount /dev/hda2 to root.
Actually, it complains about mounting /dev/vg69/root. Not /dev/hda2, 
which is your physical volume, not root filesystem. (Am I looking to a 
wrong place?)

You have a rather complex storage setup. One of the benefits of 
virtualization is that you can hide this complexity from the VM, keeping 
it very simple, very small, very stable. Caesar''s to Caesar, and 
infrastructure management to Dom0.

In this case, I bet initrd does not have LVM support, that''s why it 
can''t see /dev/vg69/root. Please consult your distribution 
documentation, about how to re-build initrd. Surely it''s a very 
automated process.
> Please give your advise what can I do.
Consider this steps:
1. Boot using the VM using your distribution''s live CD in some
"rescue"
mode.
2. Make sure your /dev/hda, and all it''s partitions and logical volumes
are readable and mountable.
3. Threat this case as a normal, not virtualized machine that got 
something wrong with it''s booting. Suse documentation shall cover it.


-- 
Alexandre Kouznetsov

Hello. Alexadre.
    I post it in the web site. Can you log on it to check
http://xen.1045712.n5.nabble.com/How-to-change-VM-from-para-virtualization-to-full-virtualization-td5712201.html.

You can see all the scree shot there. 

Looking forward your quick response.

Thanks. 


Jing Chen

CBC/XIB/K
No.5 Lize East Street, Chaoyang District
100102, Beijing, China
Phone +86 10 84767586
Mobile +86 13801223973
jing.chen@ericsson.com
www.ericsson.com  


   

This Communication is Confidential. We only send and receive email on the basis
of the terms set out at www.ericsson.com/email_disclaimer

-----Original Message-----
From: xen-users-bounces@lists.xen.org [mailto:xen-users-bounces@lists.xen.org]
On Behalf Of Alexandre Kouznetsov
Sent: Saturday, November 10, 2012 12:54 AM
To: xen-users@lists.xen.org
Subject: Re: [Xen-users] How to change VM from para-virtualization to
full-virtualization?

Hello, Jing.

(Sorry if this is repeated. I don''t see this mail I sent since
yesterday in the list, so I re-send it.)

It''s something wrong with your e-mail formatting, the screenshots you
attached are not displayed inline.

Please consider not using HTML formatting when sending mails to the list. If you
wish to share the output you get from your system, post or attach it as plain
text.

El 08/11/12 01:53, Jerry Gao escribió:
> *From: *Jing Chen
> *Sent: *Thursday, November 08, 2012 2:14 PM
>       This is Jing and I work with Jerry for this issue. I saw your 
> email and do some test following your instruction. As our case, I met 
> lots of issues since there are lots of track as you said. I list them 
> here and need your help to check.
> Seems it is a little bit longger. But your help is grateful.
> I create a PV for DomU and install the SUSE linux 11 SP2. my 
> configurations are as below.
> 1) partition.
I guess this is the screenshot showing "expert partitioner". As I
understand it, this is how your PV guest looks initially and you use
/dev/xvda2 as LVM physical volume. /dev/xvda2 seems to be a true partition
within /dev/xvda, to you already have a partitioned block device for you HVM.
> 2) /etc/fstab file
Looks fine to me. Since your guest uses LVM, the device names are expected to
remain unchanged after you switch to HVM, except /dev/xvda1 for /boot.
> 3) /boot/grub/menu.lst
>      in PV, grub has been installed. The option 0 is the one work 
> normally in PV. I add the second option for HVM.
Note, that since your /boot is on separated partition, the path to kernel and
initrd are wrong. As you specify it, they would be searched under /boot/boot.
Remove the "/boot" prefix from pathnames of kernel and initrd images,
your files are on "root" of your /boot partition.
> 4) the conf file in Dom0 is as below.
As I see, your DomU''s xvda resides on your Dom0''s /dev/sda4.
This is not something I would recommend becouse of risk of confusion, one
between many others). But should work if you are careful enough.

As a note, personally I use LVM within Dom0 (not DomU) and export multiple
logical volumes as the DomU needs them. This instead of exporting a single block
device and manage it''s volumes within DomU.
> To chagne PV to HVM. I do the following modification.
> 5) change conf file in Dom0
boot="d" should make you boot from CDROM, I''m not sure if
that''s your intention.
In any case, it''s good idea to boot a liveCD first, specially to take a
look how the storage is presented to the DomU and make sure the boot loader is
correctly installed.

So, does it boots from ISO?
> 6) change /etc/fstab as below
Looks good, but will work only if your LVM infrastructure is correctly
recognized.
> 7) change /etc/mtab as below
/etc/mtab is usually auto-generated, in rare cases it needs to be modified by
hand. In some occasion I had to do it to trick grub installer to place
it''s code in the correct place.
> Then. I start up the HVM using xm create command. And the error is as
below.
>    I try to change root parameter in menu.lst, such as
"root=/dev/hda2".
> But it still can not startup saying can not mount /dev/hda2 to root.
Actually, it complains about mounting /dev/vg69/root. Not /dev/hda2, which is
your physical volume, not root filesystem. (Am I looking to a wrong place?)

You have a rather complex storage setup. One of the benefits of virtualization
is that you can hide this complexity from the VM, keeping it very simple, very
small, very stable. Caesar''s to Caesar, and infrastructure management
to Dom0.

In this case, I bet initrd does not have LVM support, that''s why it
can''t see /dev/vg69/root. Please consult your distribution
documentation, about how to re-build initrd. Surely it''s a very
automated process.
> Please give your advise what can I do.
Consider this steps:
1. Boot using the VM using your distribution''s live CD in some
"rescue"
mode.
2. Make sure your /dev/hda, and all it''s partitions and logical volumes
are readable and mountable.
3. Threat this case as a normal, not virtualized machine that got something
wrong with it''s booting. Suse documentation shall cover it.


--
Alexandre Kouznetsov


_______________________________________________
Xen-users mailing list
Xen-users@lists.xen.org
http://lists.xen.org/xen-users

Hi, Jing.

El 11/11/12 20:02, Jing Chen escribió:
>      I post it in the web site. Can you log on it to check
http://xen.1045712.n5.nabble.com/How-to-change-VM-from-para-virtualization-to-full-virtualization-td5712201.html.
>
> You can see all the scree shot there.
I can see your screenshots. Please read the answers from my previous 
mail, the one I sent twice by mistake.

It seems like you are almost set up. Your HVM DomU will probably work 
after it get LVM support in it''s initrd. The setting
"root=/dev/hda2"
has nothing to do there, your kernel''s "root=" parameter is
fine as it
is, do not change it.

-- 
Alexandre Kouznetsov

Hi Alexandre.
    Just like last screeshot shows. My DomU can not start up since it
"Could not find /dev/vg69/root". When it ask "Want me fo fall
back to /dev/hdb2?". I input Y and the result is it can not find /dev/hdb2.
Why?

I do not know which previous email you refer to. Can you send it again to me?

BTW. I am not sure if Grub is installed correctly in my PV DomU? Can you give me
instruction how to check whether grub is installed or not? From the email you to
jerry, you said PV DomU has no grub installed.


Regards. 


Jing Chen

CBC/XIB/K
No.5 Lize East Street, Chaoyang District
100102, Beijing, China
Phone +86 10 84767586
Mobile +86 13801223973
jing.chen@ericsson.com
www.ericsson.com  


   

This Communication is Confidential. We only send and receive email on the basis
of the terms set out at www.ericsson.com/email_disclaimer

-----Original Message-----
From: xen-users-bounces@lists.xen.org [mailto:xen-users-bounces@lists.xen.org]
On Behalf Of Alexandre Kouznetsov
Sent: Monday, November 12, 2012 3:30 PM
To: xen-users@lists.xen.org
Subject: Re: [Xen-users] How to change VM from para-virtualization to
full-virtualization?

Hi, Jing.

El 11/11/12 20:02, Jing Chen escribió:
>      I post it in the web site. Can you log on it to check
http://xen.1045712.n5.nabble.com/How-to-change-VM-from-para-virtualization-to-full-virtualization-td5712201.html.
>
> You can see all the scree shot there.
I can see your screenshots. Please read the answers from my previous mail, the
one I sent twice by mistake.

It seems like you are almost set up. Your HVM DomU will probably work after it
get LVM support in it''s initrd. The setting "root=/dev/hda2"
has nothing to do there, your kernel''s "root=" parameter is
fine as it is, do not change it.

--
Alexandre Kouznetsov





_______________________________________________
Xen-users mailing list
Xen-users@lists.xen.org
http://lists.xen.org/xen-users

El 12/11/12 03:52, Jing Chen escribió:
> My DomU can not start up since it "Could not find
/dev/vg69/root".
Your "/" resides over a LVM volume. As far as there is no support for 
LVM in your running kernel, it will not find your "/" filesystem, just
the way it happens now.
> When it ask "Want me fo fall back to /dev/hdb2?". I input Y and
the result is it can not find /dev/hdb2. Why?
It''s not "/" what resides over /dev/hdb2, but
"/boot". So, even if it
fall to /dev/hdb2, it does not find there things it needs.
> I do not know which previous email you refer to. Can you send it again to
me?
The one from 2012-11-08, I''m sure you have overlooked it. In any case,
I
have sent it once again, to you directly.
> BTW. I am not sure if Grub is installed correctly in my PV DomU?
> Can you give me instruction how to check whether grub is installed or not?
Since your system actually attempts to boot, I see no way how would that 
happen without a boot loader. Judging by your screenshots, it is 
installed correctly within your DomU.
> From the email you to jerry, you said PV DomU has no grub installed.
That is correct. In PV mode, the boot loader task is performed outside 
of the virtual machine. When moving to HVM, a boot loader within VM is 
needed.

-- 
Alexandre Kouznetsov

Hi Alexandre.
    
> My DomU can not start up since it "Could not find
/dev/vg69/root".
Your "/" resides over a LVM volume. As far as there is no support for
LVM in your running kernel, it will not find your "/" filesystem, just
the way it happens now.

My kernel is SUSE linux 3.0.13-0.27-default which support the LVM. I have
another HVM using this kernel and run LVM well. Is it possible to set the
"/" resides in LVM volume?

Regards.

Jing Chen

CBC/XIB/K
No.5 Lize East Street, Chaoyang District
100102, Beijing, China
Phone +86 10 84767586
Mobile +86 13801223973
jing.chen@ericsson.com
www.ericsson.com  


   

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-----Original Message-----
From: xen-users-bounces@lists.xen.org [mailto:xen-users-bounces@lists.xen.org]
On Behalf Of Alexandre Kouznetsov
Sent: Tuesday, November 13, 2012 12:23 AM
To: xen-users@lists.xen.org
Subject: Re: [Xen-users] How to change VM from para-virtualization to
full-virtualization?

El 12/11/12 03:52, Jing Chen escribió:
> My DomU can not start up since it "Could not find
/dev/vg69/root".
Your "/" resides over a LVM volume. As far as there is no support for
LVM in your running kernel, it will not find your "/" filesystem, just
the way it happens now.
> When it ask "Want me fo fall back to /dev/hdb2?". I input Y and
the result is it can not find /dev/hdb2. Why?
It''s not "/" what resides over /dev/hdb2, but
"/boot". So, even if it fall to /dev/hdb2, it does not find there
things it needs.
> I do not know which previous email you refer to. Can you send it again to
me?
The one from 2012-11-08, I''m sure you have overlooked it. In any case,
I have sent it once again, to you directly.
> BTW. I am not sure if Grub is installed correctly in my PV DomU?
> Can you give me instruction how to check whether grub is installed or not?
Since your system actually attempts to boot, I see no way how would that happen
without a boot loader. Judging by your screenshots, it is installed correctly
within your DomU.
> From the email you to jerry, you said PV DomU has no grub installed.
That is correct. In PV mode, the boot loader task is performed outside of the
virtual machine. When moving to HVM, a boot loader within VM is needed.

--
Alexandre Kouznetsov


_______________________________________________
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Xen-users@lists.xen.org
http://lists.xen.org/xen-users

Hello

El 12/11/12 20:17, Jing Chen escribió:
> My kernel is SUSE linux 3.0.13-0.27-default which support the LVM.
Surely it does support LVM, but it''s not build in the kernel itself. 
Instead, the initrd (INITial Ram Disk) is used, which carries the kernel 
modules (see them as "drivers") that are needed to continue booting, 
mount the "/" FS (where the rest of the modules resides), etc.
http://en.wikipedia.org/wiki/Initrd

Usually, the initrd is not distributed as a binary, instead it is build 
directly on the target system, to make sure it includes everything it 
needs, and omit everything it does not need. It''s a rather automatic 
process, so I would expect that if you just "force rebuild" your
initrd,
it will put everything in place.

Good idea to do that from a chroot environment, after booting your 
system from your distribution LiveCD. I''m not familiar with Suse at
all,
but I''m sure it''s documentation describes this process.
> I have another HVM using this kernel and run LVM well.
> Is it possible to set the "/" resides in LVM volume?
Definitely "/" can reside on a LVM volume, it''s a fairly
common setup.
If your other HVM system is similar to the one you are trying to get 
work, you may try to copy it''s initrd to your "XVM69"
machine. That
would be dirty, but simple, in case you don''t get your system booting
by
other means and re-build it''s initrd natively.

I have seen the mail you sent me.
The path of the kernel and inird are relevant only on the boot loader 
stage. If you get past that point, you may conider you have a working 
configuration of that component.
The boot from a LiveCD is the way I suggest to fix your booting. Once it 
works, your regular configuration shall become boot="c".


As a separate matter, please consider using some standard way to quote 
the sender''s messages, otherwise your replay is difficult to read (even
difficult to find). Allow me to suggest you some reference:
http://en.wikipedia.org/wiki/Posting_style
http://lipas.uwasa.fi/~ts/http/quote.html

Greetings.

-- 
Alexandre Kouznetsov