Amount of virtual disks with KVM

Amount of virtual disks with KVM

[Daniel Bareiro]

[-- Attachment #1: Type: text/plain, Size: 1487 bytes --]

Hi all!

I'm trying to make a migration of a Xen PV virtual machine to KVM. For
this I'm starting a VM with SystemRescueCD [1] of the following way:

# /usr/local/kvm/bin/qemu-system-x86_64 -hda /dev/vm/hermes-disk -boot d \
 -cdrom /space/isos/systemrescuecd-x86-1.3.2.iso -m 512 -daemonize -vnc \
 :2 -k es -localtime -hdb hermes-raiz.raw -hdc hermes-var.raw -net \
 nic,vlan=0,macaddr=00:16:3e:00:00:34 -net tap

Where hermes-disk is the disk that will use the VM in the destination
host, and hermes-raiz.raw and hermes-var.raw are the raw partitions that
was using the Xen PV virtual machine in source host.

My idea is to create the partitions in hermes-disk, to mount the raw
partitions and to do "cp -a" to the partitions created in hermes-disk,
but after boot only hermes-disk and hermes-raiz.raw are exported (like
sda and sdb). Which can be the problem?

Using VIRTIO for the raw partitions I didn't have this problem.

Something similar happened to me with a ISO of Debian netinstall. It
doesn't boot passing three disks with -hdX. But making the installation
with netinstall and two disks and after it have finished and have booted
and added a third disk, the system boots without problems. Will it be
by the same cause?

Thanks in advance for your reply.

Regards,
Daniel

[1] http://www.sysresccd.org/Main_Page
-- 
Fingerprint: BFB3 08D6 B4D1 31B2 72B9  29CE 6696 BF1B 14E6 1D37
Powered by Debian GNU/Linux Squeeze - Linux user #188.598

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]

Re: Amount of virtual disks with KVM

[Avi Kivity]

On 11/29/2009 07:58 PM, Daniel Bareiro wrote:
> Hi all!
>
> I'm trying to make a migration of a Xen PV virtual machine to KVM. For
> this I'm starting a VM with SystemRescueCD [1] of the following way:
>
> # /usr/local/kvm/bin/qemu-system-x86_64 -hda /dev/vm/hermes-disk -boot d \
>   -cdrom /space/isos/systemrescuecd-x86-1.3.2.iso -m 512 -daemonize -vnc \
>   :2 -k es -localtime -hdb hermes-raiz.raw -hdc hermes-var.raw -net \
>   nic,vlan=0,macaddr=00:16:3e:00:00:34 -net tap
>
> Where hermes-disk is the disk that will use the VM in the destination
> host, and hermes-raiz.raw and hermes-var.raw are the raw partitions that
> was using the Xen PV virtual machine in source host.
>
> My idea is to create the partitions in hermes-disk, to mount the raw
> partitions and to do "cp -a" to the partitions created in hermes-disk,
> but after boot only hermes-disk and hermes-raiz.raw are exported (like
> sda and sdb). Which can be the problem?
>
>    

-cdrom and -hdc occupy the same IDE slot (second bus, master drive).  
Try -hdd instead of -hdc.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.

Re: Amount of virtual disks with KVM

[Daniel Bareiro]

[-- Attachment #1: Type: text/plain, Size: 1501 bytes --]

Hi, Avi.

On Monday, 30 November 2009 10:18:31 +0200,
Avi Kivity wrote:

> >I'm trying to make a migration of a Xen PV virtual machine to KVM.
> >For this I'm starting a VM with SystemRescueCD [1] of the following
> >way:
> >
> ># /usr/local/kvm/bin/qemu-system-x86_64 -hda /dev/vm/hermes-disk -boot d \
> >  -cdrom /space/isos/systemrescuecd-x86-1.3.2.iso -m 512 -daemonize -vnc \
> >  :2 -k es -localtime -hdb hermes-raiz.raw -hdc hermes-var.raw -net \
> >  nic,vlan=0,macaddr=00:16:3e:00:00:34 -net tap
> >
> >Where hermes-disk is the disk that will use the VM in the destination
> >host, and hermes-raiz.raw and hermes-var.raw are the raw partitions
> >that was using the Xen PV virtual machine in source host.
> >
> >My idea is to create the partitions in hermes-disk, to mount the raw
> >partitions and to do "cp -a" to the partitions created in
> >hermes-disk, but after boot only hermes-disk and hermes-raiz.raw are
> >exported (like sda and sdb). Which can be the problem?

> -cdrom and -hdc occupy the same IDE slot (second bus, master drive).
> Try -hdd instead of -hdc.

Perfect! With -hdd and -cdrom, it exported the three disks and the ISO
without problems. That would also explain why when not using -cdrom, the
-hdc disk yes it is exported after to have installed with netinstall.

Thanks for your reply.

Regards,
Daniel
-- 
Fingerprint: BFB3 08D6 B4D1 31B2 72B9  29CE 6696 BF1B 14E6 1D37
Powered by Debian GNU/Linux Squeeze - Linux user #188.598

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]