since quite a while I'm having issues and finding bugs in combination with offload/object storage and last week, I've "found" another issue, which is maybe due to the new BCJ copy mode. My support engineer (T2) wrote me the following:
Now I needed to create a new BCJ. Now there's no need to blame anyone for that, the only thing that always annoys me is the fact that due to a new BCJ, you loose the whole deduplication-benefit on s3 and unfortunately it's not the first time that I had to start with a new chain/BCJ due to issues.
Also, I tried to quickly recreate the chain of events that lead to the error, and here's what I noticed:
1. On 03.06 you disabled the job in the middle of merge:
[03.06.2020 17:51:50] <01> Error Transform step failed
[03.06.2020 17:51:50] <01> Error Job has been disabled by user VEEAM\admin (Veeam.Backup.Common.CDisableSessionException)
2. Since then it began to fail with the same error on every run:
[03.06.2020 18:02:26] <01> Error Unable to create a restore point: some backup files backing previous restore points are offloaded, please run an active full backup (System.Exception)
3. Until you forced active full on 05.06, after which it failed with the DB error:
[05.06.2020 17:26:13] <01> Info Violation of UNIQUE KEY constraint 'UQ_CryptoKeyRecoveryRecs_EncryptedKeyId_RecoveryKeyId'. Cannot insert duplicate key in object 'dbo.CryptoKeysRecoveryRecs'. The duplicate key value is (221bc60a-56bc-4584-862b-8d30e7a434c4, 83898d5a-41b0-44aa-ae15-d921dd25f8f6).
[05.06.2020 17:26:13] <01> Info The statement has been terminated.]
[05.06.2020 17:26:13] <01> Error Microsoft SQL server hosting the configuration database is currently unavailable. Possible reasons are heavy load, networking issue, server reboot, or hot backup.
So it looks like it was the cancelled merge that caused the error. Moreover, it might be that it caused the other error too.
Just wanted to post this case here so that the product can be improved.