If you followed the LINSTOR user’s guide section that uses DRBD Reactor to make the LINSTOR controller highly available, you need at least three nodes in your cluster. This is because DRBD Reactor uses DRBD’s quorum status to promote resources.
Keepalived or Pacemaker could be used instead when you only have two nodes.
You shouldn’t lose any data. Perhaps the writes are stuck in buffers somewhere. Try adding a sync
to your script to test this:
#!/bin/bash
duartion=300
for((i0; i<$duartion; i++)) do
current_time=$(date +"%Y-%m-%d %H:%M:%S")
echo $current_time >> foo.txt; sync
echo $current_time
sleep 1
done