4 identical nodes | I need some recommendations

[FlorinMarian]

Hello!
I currently have 4 identical dedicated servers, each with:
2x E5-2680v4
192GB of RAM
6x 1.2TB SSD
2x 10Gbps SFP+

My question is:
What is the recommended setup so that the data is replicated at least once (similar to RAID1 or RAID10, ceph shared storage with 3 nodes) and at the same time, I can easily restart one node at a time, without downtime on the hosted KVM machines?

I mention that I use WHMCS and each KVM machine has its own credentials. I tested the new `qm remote-migrate' feature and the migration from one server to another works great even if the servers are not in the same cluster, but apparently there is no possibility to migrate the credentials attached to the migrated VM.
Thank you!

 

[jdancer]

I have a 4-node R630 setup but using SAS drives and no SSDs. The default Ceph replication of 3/2 works fine. Can do maintenance on 1 node while the other 3 still have quorum.


Technically should have a QDevice for production but since this setup is a test cluster, I'm OK with just 4.