How to reinstall nas system

Recently, my nas server failed to respond several times， so I contacted customer care. He told me it is caused by my previous system upgrade.He said that better not to upgrad the system automatically to the latest verson from a very old system version. The suggestion is to reinstall the whole system.

My system is installed in the first disk which is /mnt/md0. Apart from the OS, docker is also installed there as well as my mysql database files. Before reinstall the system, what we should always do is to backup. It took me several hours to backup all the important file into my third disk.

Then, I followed below procedures to install OS.

1. shutdown nas
2. take out all the disks and then start nas
3. search nas using the tnas application, then click login.It will open up a webpage to access http://nasip/. At this time, the page indicates no disks are detected.
4. put all the disks back to nas. then refresh the webpage. it says

1. should it load the tos system since there is one installed in the disk
2. re install tos system