[Gluster-users] issue with GlusterFS to store KVM guests

Whit Blauvelt whit.gluster at transpect.com
Sat Jul 30 18:40:42 UTC 2011

On Sat, Jul 30, 2011 at 04:33:00PM +0530, Anand Avati wrote:

> Looks like your VM image is being attempted to open with O_DIRECT flag which is
> not supported in FUSE at the moment. You may try to configure your libvirt/qemu
> settings to open the VM without O_DIRECT. If not you may find https://
> github.com/avati/liboindirect useful.

There's a May 11 post from Aaron Roberts saying:

  I'm guessing you're using qemu-kvm?  If so, qemu-kvm will use O_SYNC
  (cache=writethough) to open a raw disk image and O_DIRECT (cache=none) to
  open a .qcow2 image.

Would it then be accurate to say that fuse and qemu are currently compatible
for raw kvm images, but not for qcow2 images? If so, that would explain why
it's been working okay in my instance. I use raw images, which are said to
be faster, if lacking qcow2 features like internal snapshotting.


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