Hi giorgiobusoni!
Well I haven't heared about this scenario and about that it is officially supported regarding ITMS environment, but I did Windows 2012 R2 Server OS upgrade to Windows Server 2016 OS, when there was ITMS 8.5 RU2 released build installed. As result, it went good and after Server OS upgrade, I didn't observe issues, SMP Console works fine, NS logs weren't saying about problems with processing internal tasks, etc and packages were remaining as well as all other items, settings, resources, managed clients & Site Servers are successfully communicating-working with ITMS.
You can try, but no guarantee that upgrade will doesn't produce unexpected issues. Who knows...
So before Windows Server OS upgrade where ITMS 8.5.x is running, better to have a backups like:
- - Backup KMS data via Symantec Management Installation manager
- - Backup existing Patch Update packages, Software Management Solution packages and settings via "Migration WIzard" (It will gather and store physical packages into 'Store.adb' file, so pay attention to have enough free space where to store them as backup if they are locally on NS server)
- - Backup Deployment Solution ghost images files.
- "Symantec_CMDB" database backup (Other databases backup if you are using Workflow, Service Desk, etc) in case if SQL Server onbox with ITMS.
Or just take Image of current Windows Server OS with working ITMS to make possible to restore everything after image restore and return back working Server OS with ITMS.
Thanks,
IP.