I migrated a Menalto Gallery 2 website, and I also got this error right away.
Error (ERROR_STORAGE_FAILURE)
This was after I fixed the permissions issue shown here: Error (ERROR_PLATFORM_FAILURE)
Searching the G2 forums, I didn’t really find anything that was very helpful, except for a few complaints about the php function mysql_pconnect().
This of course led me to realize that I probably never even migrated the database. Yup, that was it. I just needed to move the database over and update the gallery’s config.php file. This worked!
So if you’re getting this error, make sure your database is there and connected before digging any deeper. Hope this helps someone!