[CentOS] query regarding virtual machine space increase

Sat Jan 1 03:53:36 UTC 2011
Ryan Wagoner <rswagoner at gmail.com>

On Mon, Dec 27, 2010 at 1:21 PM, benedict dcunha
<sylvan.dcunha at gmail.com> wrote:
> Now when it comes to the page for specifying the disk space i see the
> following
> as warning
> (if you don't allocate the entire disk now , space will be allocated as
> needed  while the virtual machine is running)
> Now as per the message i was thinking that I would just give the minimum
> space for the OS and xen would allocate space as I install software and put
> data and files as required
> So guess basically I was wrong in interpreting the message
> Now I began to understand and as leen says .. the space specified in the
> wizard is the maximum and Xen in no way will allocate more space than
> specified in the wizard
> so it above message basically means that space is allocated and managed  by
> xen within the maximum space specified in tghe wizard.

The virtual disk works just like a hard drive. If you create a 80GB
hard drive it reports it to the guest OS as a 80GB hard drive. The
"don't allocate the entire disk now" message is about how the host OS
creates the virtual disk file. If you don't allocate it up front you
end up with a sparse file. du and df commands will show the space
actually used. ls will show you the actual file size which would be