problem swapping to backup server

[boxyball]

I had to switch to a backup server which had same roundcube version 1.1.4 as the prime.
I copied all the /var/spool/mail over and everything looked good - I was able to log into roundcube.
But when I copied the roundcube mysql database over I started getting CONNECTION TO STORAGE SERVER FAILED and could no longer log in.
So then I reinitialized the roundcube database with mysql.initial.sql and tried just copying over the following tables...

contactgroupmembers
contactgroups
contacts
identities
users

... same problem.
I need to preserve users & identities as well as contacts when switching to a backup server.
What did I miss?

Thanks in advance.

[SKaero]

The "Connection to storage server failed" error message mean that Roundcube couldn't connect to the IMAP server. Its not referring to the Roundcube database.