So. Finally I took the time for investigating and trying to progress.
After applying ILM my beats indices dissapaired from the multirole nodes and started to get created in the datanodes. At that point I've reconfigured the three multiroles nodes to be just masternodes:
node.roles: [ master ]
At that point the environment failed when I tried to start it reporting that a node that contains shards can't stop being a datanode. And the thing is that beat indices are just a part of the whole index set.
So what I've done is transfering the rest of shards from my multirole nodes with IP's: 111, 112 and 113 to my Datanodes with IP's 115 and 116
So I went to the 'Dev Tools' console and run:
PUT _cluster/settings
{
"persistent" : {
"cluster.routing.allocation.require._ip" : ["192.168.0.115", "192.168.0.116"]
}
}
PUT _cluster/settings
{
"persistent" : {
"cluster.routing.allocation.exclude._ip" : ["192.168.0.111", "192.168.0.112","192.168.0.113"]
}
}
Some minutes later 100% of indices had moved into the datanodes. Not just the beat's ones like before.
And since I did that I could change the multirole nodes into simply masternodes.
I restarted the 5 nodes and everything seems to work fine. Dashboards, HA, ingestions, etc...
Thanks all for your help.
Carlos T.