Hello.
After upgrading AOS and AHV (upgraded from AOS 5.10.1 to 6.5.3.5), I attempted to upgrade from Files 3.20 to 4.2.1.1.
The first attempt to upgrade the File Server out of a total of four File Servers failed.
After the VM update and VM NIC update, the VM change power state experienced a long time of Hang, and after 30 minutes the "File server upgrade task Hung for too long" alert was generated.
An hour later, the "File Server upgrade task stuck" alert was generated and the File Server task stopped at 44%.
I tried to force restarting that server and restarting all file servers, but it was not resolved.

After restarting all file servers, the afs command was also unavailable on the CVM.

The cluster status of the file server that attempted the upgrade is currently in the DOWN state.
The Minerva service does not start and does not start the cluster.
The shares of the files are serviced by NFS, the connection is normal, and the data can be read/write normally.

However, Data Protection (DP) has stopped due to a File Server failure, and the failed file server cannot be recovered. (Client side IP for that server is assigned to another file server. function of Minerva_HA.)

Currently, the upgrade task has been canceled through the argon command.

This is the NX3060-G5 model I purchased through ASP, and I can't open the case because there is no warranty.

Please help me if you have experienced the same or similar phenomenon as me or if you know a solution.

Attach the console screen and alert message of the failed server.