I have one ERP next on my laptop on Vritualbox. I have taken the Ova of this machine and we are installing same into on desktop at office. The laptop one will be master and desktop one will be slave. I need to update the data on desktop server from laptop serve. Is there any possible way. So that the Laptop Virtual box hosted ERPnext will act as master and the other as slave. So people can work on either one and both gets data synchronized periodically or manually by running any command.
You are discussing Master-Master replication but calling it Master-Slave replication.
In the latter, Slaves pull changes from the Master. The Master never pulls changes from Slaves.
The setup @avc references is Master-Slaves. It’s purpose is to have continuous replication across the Internet to 100% distinct Slave environments (different hosting service, different backbone, different electricity, different political jurisdiction, etc). In the event of failure of the Master any one of the Slaves can be used immediately as the new main server.
In that setup, data availability on the Slaves may end up delayed a few seconds. That is totally unacceptable for the Master-Master replication you are looking for.
Despite the above, it seems as though you are using ERPNext as though it is a desktop app like Microsoft Word where you need a copy in every machine. It is not like that. You can have hundreds of users connected to one copy of ERPNext using any browser.
You can rent a Virtual Private Server (VPS) anywhere on the Internet, such as Digital Ocean, Go Daddy, whatever, install ERPNext on it and connect to it from your laptop, with no need for an ERPNext installation on your laptop.
Adding to excellent advice by @MartinHBramwell I would suggest that you go the VPS route if HA is not a concern. Make sure you set db back to 4 or 6 times daily. You can use our app to backup to other sites like OneDrive, Google Drive etc. if you want to store backup db remotely in case there’s a failure on your VPS.