In my many hours of researching the various KVM image formats, I've finally decided on which to use but after implementing my choice I'm a bit confused. I was planning on using VMDK (VIRTIO) because it performed better under my local tests and because I was told it was considered "thin storage" (storage is increased as usage grows) and raw format is considered "thick storage" (storage is created at the max size so that space is considered unusable by the rest of the hardware node).
So I setup my KVM VM with VMDK (VIRTIO) and noticed horrible performance for the VM after building it, not sure why but that's not the point of this thread. I built an identical KVM VM but used raw (VIRTIO) but when looking under Storage under the "Used" column it didn't increase 200GB (size of the VM) yet when I look at the .raw file in /var/lib/vz/images/### it does show 200GB. Why is this? Is the raw format not really "thick storage"? If somebody can enlighten me it would be greatly appreciated.
So I setup my KVM VM with VMDK (VIRTIO) and noticed horrible performance for the VM after building it, not sure why but that's not the point of this thread. I built an identical KVM VM but used raw (VIRTIO) but when looking under Storage under the "Used" column it didn't increase 200GB (size of the VM) yet when I look at the .raw file in /var/lib/vz/images/### it does show 200GB. Why is this? Is the raw format not really "thick storage"? If somebody can enlighten me it would be greatly appreciated.
