I want to propose the unification of the available methods to synchronize two ns7 instances and to upgrade ns6 to ns7 via rsync.
We developed both Upgrade with rsync and HotSync modules over Disaster recovery and the
rsync command. By looking at how they are used, and how they are implemented I see they have a lot in common and I think we can make them one. For instance HotSync is said to be designed to quickly recover an hardware failure:
HotSync aims to reduce downtime in case of failure, syncing your NethServer with another one, that will be manually activated in case of master server failure.
…However I see it is used also as a tool to migrate to a different hardware. This is the same use case of ns6 upgrade via rsync procedure: migrate a ns6 system to a new ns7 system, on a different (newer) hardware. This is what the manual says about the rsync upgrade procedure
The process is much faster than a traditional backup and restore, also it minimizes the downtime for the users.
Furthermore if the ns6 hardware is still good I see somebody uses the two procedures together, following a two-steps upgrade path:
- temporarily upgrade ns6 to ns7 via rsync on a spare system
- use hotsync to move back the spare ns7 system to the ns6 hardware
This is actually equivalent to a live upgrade of ns6 to ns7, which is still under development.
By unifying the two procedures we can simplify both of them and reduce the risk of error due to the great number of manual operations and checks that they require today. I think we’re still too far from “simplifying the sysadmin’s life” on this field
What do you think? Can it be useful? /cc @dev_team