[sheepdog-users] qemu-img convert; vdi write and preallocation

Valerio Pachera sirio81 at gmail.com
Fri Mar 22 21:02:58 CET 2013

Hi, correct me if I'm wrong:

'qemu-img convert' will create a vdi with no preallocation.
It doesn't matter if it's from a qcow2 or a raw file.
There is no way to make it pre-allocated.

'collie vdi write' do not create the vdi.
I create a not preallocated disk and, when collie writes on it, it
will copy all the "space" form the file it reads from (also the empty
There is no way to "free" the empty space allocated on a vdi.

This is the vdi list from the cluster where I imported the 100G device
There is also a previous "test" of 100M made by 'vdi write'  form a file.

  Name        Id    Size    Used  Shared    Creation time   VDI id  Copies  Tag
  zimbra_backup     0  100 GB  100 GB  0.0 MB 2013-03-22 09:20
2e519     2
  test         0  100 MB  100 MB  0.0 MB 2013-03-22 08:21   7c2b25
  wheezy       0   10 GB  1.8 GB  0.0 MB 2013-03-20 17:02   9533ed
  squeeze      0   10 GB  292 MB  1.5 GB 2013-03-21 11:21   a34c73     2

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