Hi,
The fact that volume requests (in particular deletions) are coupled with
certain Cinder hosts is not ideal from an operational perspective:
if the node has meanwhile disappeared, e.g. retired, the deletion gets stuck
and can only be unblocked by changing the database. Some
people apparently
The problem is that the scheduler doesn't currently have enough info to
know which backends are 'equivalent' and which aren't. e.g. If you have 2
ceph clusters as cinder backends, they are indistinguishable from each
other.
On 8 January 2015 at 12:14, Arne Wiebalck arne.wieba...@cern.ch wrote:
Arne,
I imagine this has an
impact on things using the services table, such as “cinder-manage” (how
does your “cinder-manage service list” output look like? :-)
It has indeed. I have 3 cinder-volume services, but only one line output in
“cinder-manage service list”. But it's a minor
Hmm. Not sure how widespread installations with multiple Ceph backends are
where the
Cinder hosts have access to only one of the backends (which is what you assume,
right?)
But, yes, if the volume type names are also the same (is that also needed for
this to be a
problem?), this will be an
Hi,
Some people apparently use the ‘host’ option in cinder.conf to make the
hosts indistinguishable, but this creates problems in other places.
I use shared storage mounted on several cinder-volume nodes, with host
flag set the same everywhere. Never ran into problems so far. Could you
elaborate
There are races, e.g. do snapshot and delete at the same time, backup and
delete at the same time, etc. The race windows are pretty tight on ceph but
they are there. It is worse on some other backends
On 8 January 2015 at 17:50, Jordan Pittier jordan.pitt...@scality.com
wrote:
Hi,
Some people
Hi Jordan,
As Duncan pointed out there may be issues if you have multiple backends
and indistinguishable nodes (which you could probably avoid by separating
the hosts per backend and use different “host” flags for each set).
But also if you have only one backend: the “host flag will enter the
