SQL Server Bulk Migration I have production database with a size of 1TB in SQL Server 2008. I can't close the database for backup/restore process, because it needs so long time for perform this operation. 

How to migrate this database to another server which has SQL Server 2016?

I am thinking of creating a database on the new server and then bulk inserting the existing data. But what about logins, roles, permissions? How to figure it out this problem ?

Thanks,
You dont need to close the database for backup, just setup log-shipping with two servers (legacy and target), once you decide to migrate (cut-over) to target server just take log backup from legacy server and restore on target server "with recovery".