[sheepdog] Questions on the virtual disk's cache type

[Liu Yuan]

On 01/23/2013 07:26 PM, Daniel P. Berrange wrote:
> How is the cache path changed ? AFAIK, there's no way todo this in libvirt
> yet. What is path used for the VM specific directory ? This needs to be
> put into the SELinux/AppArmour policies otherwise sheepdog will just
> crash & burn when used in a environment with those active.

Well, I think libvirt doesn't need care about how sheepdog implement its
cache nor the VMs. The object cache is located on the node where the
sheep daemon runs. For e.g,

              kernel                   network
  VM on node A ---> QEMU emulated device ---> sheep daemon on node B.

Then the object cache is located on the node B and is manipulated by
sheep daemon solely.

The object cache patch is set on sheep side (NOT QEMU) when sheep daemon
starts up and never get changed later.

I don't get your SElinux/AppArmour wanring but I have run without
problems with object cache enabled so far.

Thanks,
Yuan