Hi Alwin,
On 12/16/18 7:47 PM, Alwin Antreich wrote:
On Sun, Dec 16, 2018 at 05:16:50PM +0100, Frank Thommen wrote:
Hi Alwin,
On 16/12/18 15:39, Alwin Antreich wrote:
Hello Frank,
On Sun, Dec 16, 2018 at 02:28:19PM +0100, Frank Thommen wrote:
Hi,
I understand that with the new PVE release PVE hosts (hypervisors) can be
used as Ceph servers. But it's not clear to me if (or when) that makes
sense. Do I really want to have Ceph MDS/OSD on the same hardware as my
hypervisors? Doesn't that a) accumulate multiple POFs on the same hardware
and b) occupy computing resources (CPU, RAM), that I'd rather use for my VMs
and containers? Wouldn't I rather want to have a separate Ceph cluster?
The integration of Ceph services in PVE started with Proxmox VE 3.0.
With PVE 5.3 (current) we added CephFS services to the PVE. So you can
run a hyper-converged Ceph with RBD/CephFS on the same servers as your
VM/CT.
a) can you please be more specific in what you see as multiple point of
failures?
not only I run the hypervisor which controls containers and virtual machines
on the server, but also the fileservice which is used to store the VM and
container images.
Sorry, I am still not quite sure, what your question/concern is.
Failure tolerance needs to be planned into the system design, irrespective
of service distribution.
Proxmox VE has a HA stack that restarts all services from a failed node
(if configured) on a other node.
https://pve.proxmox.com/pve-docs/chapter-ha-manager.html
Ceph does selfhealing (if enough nodes
are available) or still works in a degraded state.
http://docs.ceph.com/docs/luminous/start/intro/
Yes, I am aware of PVE and Ceph failover/healing capabilities. But I
always liked to separate basic and central services on the hardware
level. This way if one server "explodes", only one service is affected.
With PVE+Ceph on one node, such an outage would affect two basic
services at once. I don't say they wouldn't continue to run
productively, but they would run in degraded and non-failure-safe mode -
assumed we had three such nodes in the cluster - until the broken node
can be restored.
But that's probably just my old-fashioned conservative approach. That's
why I wanted to ask the list members for their assessment ;-)
[...]
Cheers
frank
_______________________________________________
pve-user mailing list
pve-user@pve.proxmox.com
https://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-user
