2 Mar
2021
2 Mar
'21
10:14 p.m.
Hello Dave,
I recommend you read this docu:
https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/3/html/a…
Regards, Joachim
___________________________________
Clyso GmbH - Ceph Foundation Member
Am 02.03.2021 um 13:55 schrieb Dave Hall:
> Dave,
>
> Just to be certain of the terminology,
>
> -----
> Step before Step 4: Quiesce client systems using Ceph
>
> Step 4: Turn off everything that's not a MGR, MON, or OSD.
>
> Step 5: Turn off OSDs
>
> Step 6: Turn off MONs
>
> Step 7: Turn off MGRs
>
> If any of the above are running on the the same nodes (i.e. mixed nodes),
> use OS capabilities (systemd) to stop and disable so nothing auto-starts
> when the hardware is powered back on.
> ----
>
> Regarding my cluster: Currently 3 nodes with 10GB front and back networks,
> 8 x 12 TB HDDs per node with Samsung 1.6TB PCIe NVMe cards. The NVMe was
> provisioned to allow adding 4 more HDDs per node, but the RocksDBs are
> proving to be a bit too small.
>
> We will shortly increase to 6 OSD nodes plus 3 separate nodes for MGRs,
> MONs, MDSs, RGWs, etc. We will also add Enterprise M.2 drives to the
> original nodes to allow us to increase the size of the caches.
>
> -Dave
>
> --
> Dave Hall
> Binghamton University
> kdhall(a)binghamton.edu
>
> On Tue, Mar 2, 2021 at 4:06 AM David Caro <dcaro(a)wikimedia.org> wrote:
>
>> On 03/01 21:41, Dave Hall wrote:
>>> Hello,
>>>
>>> I've had a look at the instructions for clean shutdown given at
>>> https://ceph.io/planet/how-to-do-a-ceph-cluster-maintenance-shutdown/,
>> but
>>> I'm not clear about some things on the steps about shutting down the
>>> various Ceph components.
>>>
>>> For my current 3-node cluster I have MONs, MDSs, MGRs, and OSDs all
>> running
>>> on the same nodes. Also, this is a non-container installation.
>>>
>>> Since I don't have separate dedicated nodes, as described in the
>> referenced
>>> web page, I think the instructions mean that I need to issue SystemD
>>> commands to stop the corresponding services/targets on each node for the
>>> Ceph components mentioned in each step.
>> Yep, the systemd units are usually named
'ceph-<daemon>@<id>', for example
>> 'ceph-osd@45' would be the systemd unit for osd.45.
>>
>>> Since we want to bring services up in the right order, I should also use
>>> SystemD commands to disable these services/targets so they don't
>>> automatically restart when I power the nodes back on. After power-on, I
>>> would then re-enable and manually start services/targets in the order
>>> described.
>> Also yes, and if you use some configuration management or similar that
>> might
>> bring them up automatically you might want to disable it temporarily too.
>>
>>> One other specific question: For step 4 it says to shut down my service
>>> nodes. Does this mean my MDSs? (I'm not running any Object Gateways or
>>> NFS, but I think these would go in this step as well?)
>> Yes, that is correct. Monitor would be the MONs, and admin the MGRs.
>>
>>> Please let me know if I've got this right. The cluster contains 200TB
>> of a
>>> researcher's data that has taken a year to collect, so caution is
needed.
>> Can you share a bit more about your setup? Are you using replicas? How
>> many?
>> Erasure coding? (a ceph osd pool ls detail , ceph osd status or similar can
>> help too).
>>
>>
>> I would recommend trying to get the hand of the process in a test
>> environment
>> first.
>>
>> Cheers!
>>
>>> Thanks.
>>>
>>> -Dave
>>>
>>> --
>>> Dave Hall
>>> Binghamton University
>>> kdhall(a)binghamton.edu
>>> _______________________________________________
>>> ceph-users mailing list -- ceph-users(a)ceph.io
>>> To unsubscribe send an email to ceph-users-leave(a)ceph.io
>> --
>> David Caro
>> SRE - Cloud Services
>> Wikimedia Foundation <https://wikimediafoundation.org/>
>> PGP Signature: 7180 83A2 AC8B 314F B4CE 1171 4071 C7E1 D262 69C3
>>
>> "Imagine a world in which every single human being can freely share in the
>> sum of all knowledge. That's our commitment."
>>
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