Ceph

Also: it has come to light that with the new Ceph behavior of defaulting to
cephx enabled, one must either

1) use libvirt 10.0 or better, to get the commit shown below, or

2) add ":auth_supported=none:" to the parameter list in the name= parameter.

libvirt commit shown below:

commit ccb94785007d33365d49dd566e194eb0a022148d
Author: Wido den Hollander <wido@widodh.nl>
Date:   Mon Jun 25 17:44:01 2012 +0200

    qemu: Always set auth_supported for Ceph disks.

    Recently the Ceph project defaulted auth_supported from 'none' to 'cephx'.

    When no auth information was set for Ceph disks this would lead to librados defaulting to
    'cephx', but there would be no additional authorization information.

    We now explicitly set auth_supported to none when passing down arguments to Qemu.

    Signed-off-by: Wido den Hollander <wido@widodh.nl>

The issue Dan's talking about only matters if you're not using cephx for clients.

The secondary issue is only without cephx, it's true, but the bigger issue of "we really
need this documentation in the official docs" is still horribly true. Please let's just extract what we had in the wiki into a page on ceph.com/docs, with just the barest review to make sure none of it
is a lie, as soon as we can; I can't remember where to find this information