This has been sitting as a draft on meta.discourse.org as I worked through the issue on my Discourse server. I’ve been able to get around the problem described below, but that I couldn’t do what was effectively a disaster restore (a restore without the benefit of being able to get into the old, broken server) is concerning. (The root cause was a failed Postgres 10-to-12 upgrade, but I was able to postpone the update in the Discourse app.yml file long enough to disable the enable_s3_uploads site setting before creating the backup. I’ve now done that backup, uploaded it to the new server, restored it, and have the Discourse site running again. Original message:
I am reconstructing a Discourse install from backup stored on S3. The old installation was very old—first installed in June 2016. I started the restore from a fresh installation because of a failed Postgres 10-to-12 upgrade. Rather than fix that…since this box was running an no longer supported version of Ubuntu…I thought I would just take the latest backup and load it onto the new server. The restore fails, however. In the logs, the point at which I’m running into a problem is here:
[2020-11-23 22:27:32] Reloading translations...
[2020-11-23 22:27:32] Remapping uploads...
[2020-11-23 22:27:32] Restoring uploads, this may take a while...
[2020-11-23 22:28:38] EXCEPTION: 465 of 751 uploads are not migrated to S3. S3 migration failed for db 'default'.
[2020-11-23 22:28:38] /var/www/discourse/lib/file_store/to_s3_migration.rb:131:in `raise_or_log'
/var/www/discourse/lib/file_store/to_s3_migration.rb:78:in `migration_successful?'
/var/www/discourse/lib/file_store/to_s3_migration.rb:357:in `migrate_to_s3'
/var/www/discourse/lib/file_store/to_s3_migration.rb:65:in `migrate'
/var/www/discourse/lib/file_store/s3_store.rb:238:in `copy_from'
/var/www/discourse/lib/backup_restore/uploads_restorer.rb:48:in `restore_uploads'
/var/www/discourse/lib/backup_restore/uploads_restorer.rb:30:in `restore'
/var/www/discourse/lib/backup_restore/restorer.rb:64:in `run'
/var/www/discourse/script/spawn_backup_restore.rb:23:in `restore'
/var/www/discourse/script/spawn_backup_restore.rb:36:in `block in <main>'
/var/www/discourse/script/spawn_backup_restore.rb:4:in `fork'
/var/www/discourse/script/spawn_backup_restore.rb:4:in `<main>'
[2020-11-23 22:28:38] Trying to rollback...
This sounds similar to Restore process cancelled at migrating uploads to S3 step - #5 by Jim.Morrison, but it didn’t offer any guidance on how to fix the issue.
The before-you-post message in the right pane of this compose window also suggested Failed to restore DB, but that didn’t have anything helpful either.