[Gluster-users] Production cluster planning

[Gandalf Corvotempesta]

Next year i'll start with our first production cluster.
I'll put on that many VMs images (XenServer, ProxMox, ...).

Currently I have 3 SuperMicro 6028R-E1CR12T to be used as storage nodes.

I'll put 2 more 10GbT cards on each.

Primary goal is to have MAXIMUM data redundancy and protection.
we can live with not top-notch performances but data protection must
be assured all the time in all conditions.

Some questions:
1) should I create any raid on each server? If yes, which level and how many?
 - 4 RAID-5 with 3 disks each ? With this i'll create 4 bricks on each server
 - 6 RAID-1 with 2 disks each ? With this i'll create 6 bricks on each
server (but space wasted is too high)
 - 2 RAID-6 with 6 disks each? With this i'll create 2 bricks on each server

2) Should I use standard replication (replicate 3) or EC ?

3) Our servers has 2 SSD in the back. Can I use this as tiering ?

4) Our servers has 1 SSD inside (not hotplug) for the OS. What would
happens in case of a crash of this SSD ? Is gluster able to recover
the whole failed node ?