Raw format x Space

[vitor costa]

The new RAW format to KVM virtual disks have a draw back: waste space. When create multiples guests with qcow2 you can provisioning max disk size (but without use it) so you can have many guests and in future, with grow, you can realocate then or add a bigger disk... now with raw or you make guests with tiny disks or wast your storage for long time.

Its any tecnical problem in use qcow2 in share storage like lvm/drbd ? Its possible support in future proxmox versions ?

 

[tom]

The new RAW format to KVM virtual disks have a draw back: waste space. When create multiples guests with qcow2 you can provisioning max disk size (but without use it) so you can have many guests and in future, with grow, you can realocate then or add a bigger disk... now with raw or you make guests with tiny disks or wast your storage for long time.

Its any tecnical problem in use qcow2 in share storage like lvm/drbd ? Its possible support in future proxmox versions ?

if you run a file system with support of sparse files (like ext3) the space is NOT pre-allocated when you use "raw". so its basically no difference to qcow2 (in term of wasting space). there are other differences.

see http://en.wikipedia.org/wiki/Sparse_file

if you use block devices directly (LVM2, DRBD, ...) always the whole space is allocated (always raw) - behavior by design.