The Virt-Manager Storage Disks Fedora 18 host.

[Frank Murphy]

I have 5 physical disks, on which the virt-images are stored.

What I have found is for whatever reason, I need to put a new
disk or disk-controller card into the host machine.

It can changes the order of the disks as seen by the host.
So vm's may not start as the physical disk they are on eg: /dev/sdd
is now /dev/sdf or or /dev/sdc

What can I do to protect myself from this in the future.

-- 
Regards,
Frank
http//www.frankly3d.com

[Frank Murphy]

On Wed, 17 Apr 2013 23:23:06 +0200
poma <pomidorabelisima(a)gmail.com&gt; wrote:

>  On 17.04.2013 19:32, poma wrote:
>  > On 17.04.2013 17:33, Frank Murphy wrote: 
>  Hah!
>  Frank, it would be nice of you to use the correct terminology[1]. ;)
>  Your so called "virt-images" are not a virtual machines per se.
>  It is possible that you do not use physical discs as a block based
>  storage pool, nor as a storage volumes at all - but you're adding
>  them directly to guests as a physical devices. 
No storage pool correct, 
in Virt-Manager I add storage physical
disk /dev/sd*


>  So an UUID[2] is probably what you need:
>  /etc/libvirt/qemu/Magrathea.xml
>  […]
>  <disk type='block' device='disk'>
>    <driver name='qemu' type='raw'/>
>    <source dev='/dev/disk/by-uuid/x8-x4-x4-x4-x12'/>
>    <target dev='sda' bus='scsi'/>
>    <address type='drive' controller='0' bus='0'
> target='0' unit='0'/>
>  </disk>
>  […]
>  
>   
Thanks for this, confused myself also.


-- 
Regards,
Frank
http//www.frankly3d.com

[Frank Murphy]

On Wed, 17 Apr 2013 19:32:51 +0200
poma <pomidorabelisima(a)gmail.com&gt; wrote:

>  On 17.04.2013 17:33, Frank Murphy wrote:
>  > On Wed, 17 Apr 2013 15:58:20 +0200
>  > poma <pomidorabelisima(a)gmail.com&gt; wrote:
>  > 
>  >> Mount points are the mount points, regardless of the disks
>  >> layout. :)
>  
>  […]
>  
>  > What are you talking about?
>  
>  What am I talking about!? :)
>  
>  > If the stated disk in Virt-Manager is sdf for  eg Fedora-17
>  > and the host then changes it to sdg, it's still sdf in
>  > virt-Manager. Thus it complains about the image not being found.
>  
>  You haven't confirmed the first question.
>  That part you left out in this response, and it is essential to
>  clarify the problem. ;)
>  
>  poma
>   
Apologies, didn't see first part.


-- 
Regards,
Frank
http//www.frankly3d.com

[poma]

On 17.04.2013 19:32, poma wrote:
>  On 17.04.2013 17:33, Frank Murphy wrote:
> > On Wed, 17 Apr 2013 15:58:20 +0200
> > poma <pomidorabelisima(a)gmail.com&gt; wrote:
> >
> >> Mount points are the mount points, regardless of the disks
> >> layout. :)
>  
>  […]
>  
> > What are you talking about?
>  
>  What am I talking about!? :)
>  
> > If the stated disk in Virt-Manager is sdf for  eg Fedora-17
> > and the host then changes it to sdg, it's still sdf in virt-Manager.
> > Thus it complains about the image not being found.
>  
>  You haven't confirmed the first question.
>  That part you left out in this response, and it is essential to clarify
>  the problem. ;) 
Hah!
Frank, it would be nice of you to use the correct terminology[1]. ;)
Your so called "virt-images" are not a virtual machines per se.
It is possible that you do not use physical discs as a block based
storage pool, nor as a storage volumes at all - but you're adding them
directly to guests as a physical devices.
So an UUID[2] is probably what you need:
/etc/libvirt/qemu/Magrathea.xml
[…]
<disk type='block' device='disk'>
  <driver name='qemu' type='raw'/>
  <source dev='/dev/disk/by-uuid/x8-x4-x4-x4-x12'/>
  <target dev='sda' bus='scsi'/>
  <address type='drive' controller='0' bus='0'
target='0' unit='0'/>
</disk>
[…]


poma


[1]
https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Lin...
[2] http://en.wikipedia.org/wiki/Universally_unique_identifier

[poma]

On 17.04.2013 17:33, Frank Murphy wrote:
>  On Wed, 17 Apr 2013 15:58:20 +0200
>  poma <pomidorabelisima(a)gmail.com&gt; wrote:
>  
> > Mount points are the mount points, regardless of the disks
> > layout. :) 
[…]

>  What are you talking about? 
What am I talking about!? :)

>  If the stated disk in Virt-Manager is sdf for  eg Fedora-17
>  and the host then changes it to sdg, it's still sdf in virt-Manager.
>  Thus it complains about the image not being found. 
You haven't confirmed the first question.
That part you left out in this response, and it is essential to clarify
the problem. ;)

poma

[Frank Murphy]

On Wed, 17 Apr 2013 15:58:20 +0200
poma <pomidorabelisima(a)gmail.com&gt; wrote:

>  Mount points are the mount points, regardless of the disks
>  layout. :)
>  
>  poma 
What are you talking about?
If the stated disk in Virt-Manager is sdf for  eg Fedora-17
and the host then changes it to sdg, it's still sdf in virt-Manager.
Thus it complains about the image not being found.


-- 
Regards,
Frank
http//www.frankly3d.com

[poma]

On 17.04.2013 10:41, Frank Murphy wrote:
>  I have 5 physical disks, on which the virt-images are stored. 
Probably you have 5 physical disks *partitions* *mounted* on a storage
*pool* *directory* defaulting to "/var/lib/libvirt/images", right?

>  What I have found is for whatever reason, I need to put a new
>  disk or disk-controller card into the host machine.
>  
>  It can changes the order of the disks as seen by the host.
>  So vm's may not start as the physical disk they are on eg: /dev/sdd
>  is now /dev/sdf or or /dev/sdc
>  
>  What can I do to protect myself from this in the future. 
Mount points are the mount points, regardless of the disks layout. :)

poma