On 3/18/2013 8:43 AM, Donal Lafferty wrote:
AFAIK, data disks are by default created in Primary Storage and not on the 
hypervisor itself.  I take it you want the replacement server for a VM to sit 
in a different cluster that does not have access to the same primary storage

Did you mean to ask whether the data disk is a 'dyanmic' hard drive image?  
'Dynamic' disks are about as large as the actual data stored on it.  They do 
not reserve spaced in the store for portions of the disk that have no data.  In 
this case, I do not know the answer, as I've not much experience with KVM.
No I was more talking about the thin provisioning at LVM because I was considering to boot those disk less VMs with the 1GB data disk on hyper visor with local storage not to
waste precious NAS.
That's why I was thinking of thin provisioning of LVM

IIRC, 'thin' as in 'thin provisioning' relates to templates.  To reduce the 
foot print of the root device, a read/write 'diff' disk is created and linked 
to a read only 'base' disk.  The 'base' disk is a copy of the template image.  
The diff captures changes, and grows over time as the VM updates.  Because a 
number of VMs use the same 'base' image, template transfer time and the foot 
print of the root device is substantially reduced.
That's the reason why we have patchdisk files ?

-----Original Message-----
From: Teipel, Bjoern [mailto:bjoern.tei...@internetbrands.com]
Sent: 18 March 2013 3:24 PM
To: cloudstack-users@incubator.apache.org
Cc: cloudstack-users@incubator.apache.org
Subject: Re: diskless boot

Hi Donal,

I didn't try thin provisioning on a local LVM disk but I would expect that is 
takes only few MB. Does CS support thin on local storage (LVM)?

I can see where you question is going but a data disk,even empty would create a 
dependency to the hypervisor.
The idea for using disk less boot is not to create any dependency on storage 
and only rely on memory/CPU. If the hypervisor goes down I just start the VM in 
a new one.
A data disk would be here blocking and you have to remove the data disk from 
the VM before you can do any action on the VM. Doubt that would work in CS.

Bjoern

On Mar 18, 2013, at 4:00 AM, "Donal Lafferty" <donal.laffe...@citrix.com> wrote:

Let me rephrase that,

Hi Bjoern,

On the KVM deployment you are using, I take it that the 1 gig disk is a data 
disk.  It the problem that its unwieldy to manage or that 1 gig takes up too 
much room?

Does the 1 gig data disk take up a lot of space on the primary storage?

DL


-----Original Message-----
From: Mathias Mullins [mailto:mathias.mull...@citrix.com]
Sent: 18 March 2013 10:53 AM
To: cloudstack-users@incubator.apache.org
Subject: Re: diskless boot

Thin or thick provisioned? On what type of file system?

Thank you,
Matt

On Mar 18, 2013, at 9:47 PM, "Donal Lafferty" <donal.laffe...@citrix.com>
wrote:

Out of interest, how much space does an unused 1 Gig disk take up on a
hypervisor?
DL

-----Original Message-----
From: Bjoern Teipel [mailto:bjoern.tei...@internetbrands.com]
Sent: 16 March 2013 6:12 AM
To: cloudstack-users@incubator.apache.org
Subject: diskless boot

Hi guys,

one of my questions is still open:

- CS doesn't support booting over ISO only without attaching a disk.
   Background is, we migrate our datacenter to boot from ISO/PXE and
   thats a big no go for me if I'm enforced to assign a 1G disk.
   Also set the minimum disk size to 0G in the global settings but
   I can't create "No Disk" Disk offerings ...

Nobody had the desire to boot disk less other than me ?
Can't believe that ;-)

Thanks,
Bjoern

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