[fedora-virt] qcow2, raw, COW

[Gene Czarcinski]

I am not sure if this is the correct mailing list so if it is not, point 
me to the correct one.

I am a fan of the BTRFS filesystem and even use a subvolume for 
/var/lib/libvirt/images.  Now, if you don't do anything, the disk image 
files are going to be hugely fragmented and get even more fragmented 
over time since BTRFS is a copy-on-write filesystem.  I thought I knew 
how this stuff worked but apparently I do not because it does not 
currently work for me on Fedora 20 with current updates (not the preview 
although I will likely install that "real soon now").

1.  To disable C-O-W I did "chattr +C /var/lib/libvirt/images" but new 
files are showing large fragmentation.

2. I want the default disk image format to be raw rather than qcow2.  On 
one of my systems, new disk images default to raw.  On another system, 
new disk images default to qcow2.  Both are Fedora 20 and I did nothing 
to either.

3.  I tried: "sudo virsh pool-edit default" and adding "<format 
type=raw'/>" to the definition for <target>.  The command executed with 
no errors when I did ":wq" but the definition was *not* changed.

Are these bugs I need to report or is there something I need to do.

Gene
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