Confluence cannot start up and H2 database is not reachable

[Janos Nyika]

2019-05-10 10:23:50,634 WARN [C3P0PooledConnectionPoolManager[identityToken->1hgeby9a218kkyrh17optqw|3d5099ce]-HelperThread-#2] [mchange.v2.resourcepool.BasicResourcePool] log com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@46ceade9 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception:
org.h2.jdbc.JdbcSQLException: File corrupted while reading record: "page[1457153] data leaf overflow parent:1457152 next:1457154". Possible solution: use the recovery tool [90030-176]

I'm trying to use DBVisualizer tool for loging into DB but it says:

An error occurred while establishing the connection:

Long Message:
The database is read only [90097-195]

Details:
   Type: org.h2.jdbc.JdbcSQLException
   Error Code: 90097
   SQL State: 90097

[Shannon S]

Hello Janos,

Welcome to Community; it's nice to have you!

The Embedded H2 database as you may know already is useful for evaluating Confluence instances, but can cause a lot of issues when used on an instance being run as a production instance.

1. Is this an evaluation still, or a production instance?
2. When is the last time you created a full site backup?
3. What is your Confluence version?

In order to resolve this error, you will need to migrate your data to a supported database.

Please review the documentation Migrating to Another Database for details on this. Note that this does require you to have a full site backup in order to proceed.

Do let me know if you have any difficulty or roadblocks, including the above information requested and we can proceed from there!

Regards,

Shannon