[SOLVED] Adding multiple osds to a ceph cluster

[Ting]

Hi,

I have a proxmox cluster with 6 nodes, and have ceph running on it with 2 osds at each node. I want to add one extra osd at each node. My question is:

After I added an osd, should I wait for the whole ceph rebalanced first, then adding 2nd osd, and so on? Thanks.

 

[mr44er]

should I wait for the whole ceph rebalanced first, then adding 2nd osd, and so on?

That doesn't matter, the rebalancing is live...if you add the second, it will again "re-rebalance". So just add them and watch how Ceph does its magic.

 

[alexskysilk]

After I added an osd, should I wait for the whole ceph rebalanced first, then adding 2nd osd, and so on? Thanks.

It depends on your active io on the cluster. The more traffic you demand from rebalancing, the more impact it will have on your guest IO. add OSDs one by one, and see how it impacts your guest performance. when you notice it, stop and wait for completion

Alternatively, start reading about all the different tunables.

 

[Ting]

Great, that is what my main concern is. Thanks, I will monitor my guest performance first. thanks again.