VM Disk automatically deletes in SAN storage

[nitaish]

Hello,

We have setup mulitple Proxmox nodes using the same shared SAN storage. We have created multiple HA clusters with two nodes in each cluster. All are using the same LUN on the shared SAN storage. All the VMs have unique VM id so that no two VMs with the same id are present in different clusters. Off late, we are experiencing issue with the deletion of VM disk of a few VMs from the SAN storage. We have to re-create the VMs and re-deploy our application. I guess there is some setting messed up which is causing the issue. I am unable to find the reason as there is nothing available in the log files of any node. Can anyone suggest what could be wrong?

 

[dietmar]

Please do not use the same storage for different clusters. This does not work because locking does not work between different clusters.

 

[nitaish]

We have been using it from the past 3 months, only recently we came across this issue. Can you explain in detail what happens if we use the same LUN? We have not enabled "Use LUN Directly" in any cluster.

 

[dietmar]

I already explained it: locking does not work - this can result in data loss.

 

[nitaish]

Can you explain me the concept of locking in detail?

 

[dietmar]

see https://en.wikipedia.org/wiki/Lock_(computer_science)

 

[nitaish]

Afaik, the VM locking happens when the backup task is in progress. In our case, we have not set any backup.

 

[dietmar]

Again, please do not use such setup.