I am running a small - but growing - ceph-cluster at work. Since it is fun and our storage demand is growing each day.

Today, it was time to bring another node online and add another 12TB to the cluster.
Installation of the OS went fine, network settings fine, drives looks fine.

Now, time to add it into the cluster.... BAM
Every Dell machine in the Cluster - Dead.
The two HP-machines is online and running. But the Dell-machines just died.

WAT!?