Re: Large numbers of OSD per node

[Wido den Hollander <wido@widodh.nl>]

On 06-11-12 10:36, Gandalf Corvotempesta wrote:
> 2012/11/6 Wido den Hollander <wido@widodh.nl>:
>> You shouldn't only think about a complete failure solution. The distributed
>> architecture of Ceph also gives you the freedom to take out a node whenever
>> you want to do maintenance or just don't trust the node and you want to
>> investigate.
>>
>> The scenario is still the same. Use smaller nodes so taking out one node
>> (for what reason) doesn't impact your cluster that much.
>
> Here:
> http://ceph.com/docs/master/install/hardware-recommendations/
> is wrote that a production cluster has been made with many R515 with
> 12 disks of 3TB each. This give us 36TB of storage.
>
> is this configuration considered good ? I'm planning to have the same server.
> --

It works for them. There is no journaling though, but this setup is only 
being used for the RADOS Gateway, not for RBD.

You might want to insert a couple of SSDs in there to do journaling for you.

But the rule also applies here. When you use 3 of these machines, when 
loosing one, you will lose 33% of your cluster.

The setup described on that page has 90 nodes, so one node failing is a 
little over 1% of the cluster which fails.

Wido

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