Veeam 12 – SQL Log Backup Error: “Logs do not match any existing database backup

[mikkeland]

Hi all,

I’m running into an issue with SQL transaction log backups in Veeam and hoping someone can help clarify what I might be missing.

Environment:
* Veeam Backup & Replication v12 (latest)
* Nutanix AHV
* 1 × Microsoft SQL Server (likely 2019 or 2022)
* 6 online databases + several offline databases

Current setup:
* Backup job is fully functional
* Application-Aware Processing enabled
* Transaction log truncation working as expected
* Recently enabled periodic transaction log backups
* Performed a new full backup after enabling log backups

Issue:
Log backups are running and truncating logs, but I consistently get this error:

Code: Select all

Collected SQL Server transaction logs do not match any existing database backup

Relevant log snippet:

Code: Select all

[SqlLogApplicabilityChecker] Log chain for database [DBNAME] cannot be applied to a full backup
[14.04.2026 15:19:28.311]    <43>   Error (3)    [SqlLogApplicabilityChecker] Database backup: [Name=arcgis:InstanceName=:@first_LSN=14194000001969600037:@last_LSN=14194000001972800001:start_creation_time=02-04-2026 22:30:58:creation_usn=303]
[14.04.2026 15:19:28.311]    <43>   Error (3)    [SqlLogApplicabilityChecker] Prev log backup: [id=8363fd97-ec02-43b4-83a0-03108b47a9ee:guest_db_id=4b92cc3b-26dd-4e1e-a463-719397dc4dab:@first_LSN=14194000001976800001:@last_LSN=14200000002232000001:file_name={11ab91ec-6e2f-4dd4-bed7-38a079c91cb3}.bak:creation_usn=317]
[14.04.2026 15:19:28.311]    <43>   Error (3)    [SqlLogApplicabilityChecker] Next log backup: [id=8363fd97-ec02-43b4-83a0-03108b47a9ee:guest_db_id=4b92cc3b-26dd-4e1e-a463-719397dc4dab:@first_LSN=14194000001976800001:@last_LSN=14200000002232000001:file_name={11ab91ec-6e2f-4dd4-bed7-38a079c91cb3}.bak:creation_usn=317]
[14.04.2026 15:19:28.311]    <43>   Error (3)    [PrepareOperation] Log DBNAME cannot be applied

Observations:
* Log chain appears to be broken (LSNs don’t align between full and log backups)
* Veeam logs only reference **online databases** (as expected)
* Previous backups (before enabling log backups) used AAP with **truncation only**
* Restore points exist from before enabling periodic log backups

Question:
* After enabling periodic log backups and running a new full backup, I expected a clean log chain.
* Why would Veeam still report that the log backups don’t match an existing full backup?
* Is this expected behavior due to previous backup chains (pre-log-backup configuration)?
* As i have already done an active full, do I reset the chain in some way?

Any insights or similar experiences would be greatly appreciated.

Thanks in advance