Re: [ovirt-users] import thin provisioned disks with image upload

On Thu, Dec 7, 2017 at 9:33 PM, Nir Soffer <nsoffer(a)redhat.com&gt; wrote: > > For transferring images over http, there is no way to avoid sending > unused blocks, except compression. > OK, understood >> Maybe this file was crated with preallocation=full? >>> >> >> In virt-manager there is not this logic by default. >> The default format is qcow2/sparse >> When you create/add a disk you can choose "Select or create custom >> storage": >> >> https://drive.google.com/file/d/1gAwjAG5aRFC5fFgkoZXT5wINvQnov88p/view?us... >> >> And then choose a format between: >> raw, qcow, qcow2, qed, vmdk, vpc, vdi >> >> In my case it was the default one, so qcow2, as qemu-img correctly >> detects. >> > > I tested creating qcow2 files with virt manager, and it seems to use > the preallocation=metadata by default (behind your back), I guess > for improving performance in some cases. oVirt doe not use this > option so we don't have this issue when downloading files. > > Ah, ok. I didn't know about this preallocation option of qemu-img Does your example mean that by default oVirt uses preallocation=off when creating thin provisoned disks?

> I hope I convinced you this time ;-) > > Nir > Yes :- ] and thanks for the deep an detailed explanation, Nir Thanks also to Eric for his comments in the other reply Gianluca