Can the original database still be used after the database migration?

[SevenLiquor]

The problem is as stated in the title.
When I was testing migrate-db from bbotDB to postgreSQL, there was a disable flag preventing me from accessing the original database.
Although my migration test went very smoothly, the mainnet node I am preparing to migrate consists of over 200 asset channels and more than 20GB of database files.So I am very worried that there might be problems during the migration process.

If any errors occur during or after the migration process, can I use the original database to restore the nodes? Or are there any other methods to ensure that my database can be migrated correctly?

[guggero]

The migration process as implemented in lndinit migrate-db is quite fault tolerant. It migrates buckets in batches and even has the ability to resume a previously interrupted/aborted migration attempt. And it also verifies all migrated data.
There will be a "tombstone marker" that's added to the bbolt DB once the migration has completed successfully. That marker will prevent you from using it again.

So you could try out the migration on a copy, but then you have to be very careful to never start the original again if you ever started the node from a copied or migrated state.

So whatever you do, it's VERY IMPORTANT: NEVER EVER start from an old state once you've started the node from a new (copied/migrated) state OR THERE IS POTENTIAL FOR LOSS OF FUNDS. See general safety guide around file based backups.

So my recommendation is:

• Stop your node
• Make sure the Postgres instance you migrate to has ample disk space and is otherwise healthy and operational
• Run the migration on the original data but give the process enough time and make sure to not interrupt it
• Point your node over to Postgres
• Start your node

And if you run into issues in any of these step, please contact us before trying anything yourself or reverting to a potentially old state. But I don't really expect any issues, the migration has been tested on larger nodes before without problems.

[SevenLiquor]

Thank you for your answer. It gives me more confidence.(ง •_•)ง