Re: [libvirt] Using external ceph.conf for RBD pools and disks
On Fri, 1 Nov 2013, Daniel P. Berrange wrote:
We have always taken the position that we do not want to rely on
host
configuration in this way. The goal of the XML configs is that they
fully describe the functional setup of the resource in question. This
is to ensure that if you put the same XML config on two different hosts
you can be sure that they will operate in the same way. If you leave out
a bunch of config information and rely on the host ceph.conf file, then
you can no longer ever be sure if two hosts are configured the same way
with libvirt.
I suspected that might be the case -- half the reason I sent my email,
really!
If it's desireable to not rely on any host configuration at all, should we
be explicitly be passing conf=/dev/null to QEMU when setting up a RBD
device? As I mentioned before, without that QEMU will implicitly try to
find a system ceph.conf file using a built-in librados search path. Would
this actually be backwards-incompatible change given it was never
documented by libvirt?
- Michael