Troubleshooting Veeam Guest Helper Log Errors: 0x80040e14, SQL Backup Failed, and Truncation Issues

Understanding Veeam Application-Aware Processing

When Veeam Backup & Replication performs a backup of a database server (like Microsoft SQL Server or PostgreSQL), it uses Application-Aware Processing to ensure transactional consistency. This process injects a temporary runtime process into the guest OS. When things go wrong—such as backup failed for server microsoft.sqlserver.smoextended, unable to truncate transaction logs veeam, or sqlvdimemoryname_0 errors—the Veeam Guest Helper log is your primary diagnostic tool.

Where to Find the Veeam Guest Helper Log

To see the guest helper log, you must log into the target virtual machine (the SQL or Postgres server being backed up), not the Veeam Backup Server.

Navigate to: C:\ProgramData\Veeam\Backup\VeeamGuestHelper_%date%.log

This log records the step-by-step execution of the VSS (Volume Shadow Copy Service) freeze, database enumeration, and log truncation commands.

Common Error 1: 0x80040e14 and Microsoft.SqlServer.SmoExtended

One of the most frequent errors encountered is: Backup failed for Server. Microsoft.SqlServer.SmoExtended or the underlying HRESULT: 0x80040e14.

This error almost universally points to a permissions issue or a misconfiguration within SQL Server Management Objects (SMO). Veeam uses SMO to connect to the SQL instance, enumerate databases, and instruct SQL to freeze I/O. If the account specified in Veeam's Guest OS Credentials does not have the sysadmin server role within SQL Server, SMO fails to execute the necessary queries. Alternatively, this happens if the SQL Server is strictly configured to disallow NT AUTHORITY\SYSTEM access, and Veeam is falling back to the local system account.

Common Error 2: Failed to Truncate SQL Logs

A successful database backup should culminate in transaction log truncation. However, you might see: Failed to truncate SQL logs veeam or Unable to truncate transaction logs veeam.

This failure occurs for several reasons:

1. Recovery Model Mismatch: The database is set to Simple Recovery Model, but Veeam is attempting to process it as Full Recovery. Logs in Simple recovery truncate automatically; Veeam attempting it throws a warning.
2. Broken Log Chain: A manual backup was taken outside of Veeam (e.g., via SQL Server Management Studio without the 'Copy Only' flag), breaking the LSN (Log Sequence Number) chain.
3. Lack of Disk Space: SQL cannot write the truncation checkpoint because the drive holding the .ldf file is completely full.

Common Error 3: Backup Media Verification Failed

You may encounter: Backup media verification failed microsoft.sqlserver.management.relationalenginetasks or sql backup media verification failed.

This typically happens when Veeam attempts to verify the integrity of the backup metadata via SQL VDI (Virtual Device Interface), but the underlying storage experienced a micro-disconnect, or the SQL VSS Writer is in a failed state (vssadmin list writers).

Common Error 4: VDI Memory Issues (sqlvdimemoryname_0)

An obscure but critical error is related to sqlvdimemoryname_0. When Veeam requests a VSS snapshot, SQL Server uses the Virtual Device Interface (VDI) to freeze I/O. VDI requires a contiguous block of memory. If the SQL Server has been running for months and memory is heavily fragmented, it cannot allocate the VDI shared memory segment. The backup fails instantly before any data is transferred.

Common Error 5: Postgres Disk Space Full

While SQL Server has its own quirks, PostgreSQL users often face postgres disk space full errors during Veeam backups. When Veeam triggers a pg_start_backup(), Postgres begins accumulating Write-Ahead Logs (WAL) aggressively. If the backup takes a long time (e.g., a massive VM over a slow network) and the pg_wal partition is undersized, the disk fills up, Postgres crashes, and the backup fails.

Step-by-Step Resolution Guide

Step 1: Diagnosing via the Guest Helper Log

First, open C:\ProgramData\Veeam\Backup\VeeamGuestHelper.log on the SQL VM. Search for the string ERR | or Exception.

If you see Login failed for user, proceed to Step 2. If you see VDI Error or sqlvdimemoryname, proceed to Step 3. If you see The log was not truncated, proceed to Step 4.

Step 2: Resolving SMOExtended and 0x80040e14 Permission Errors

To fix backup failed for server microsoft.sqlserver.smoextended:

1. Open SQL Server Management Studio (SSMS) on the target server.
2. Navigate to Security -> Logins.
3. Locate the Windows Account you provided to Veeam for Guest Processing.
4. Right-click the account -> Properties -> Server Roles.
5. Ensure sysadmin is checked.
6. Additionally, ensure NT AUTHORITY\SYSTEM has sysadmin rights if you are using VIX/RPC fallback injection without specific credentials.

Step 3: Fixing VDI Memory and Media Verification Issues

If you encounter sqlvdimemoryname_0 or backup media verification failed, the SQL VSS Writer is likely deadlocked or out of memory.

1. Open an administrative command prompt and run vssadmin list writers.
2. Look for SqlServerWriter. If the state is anything other than [1] Stable (e.g., [8] Failed or [9] Timed out), you must restart the service.
3. Open Services (services.msc) and restart the SQL Server VSS Writer service.
4. If the error persists, the SQL instance itself is fragmented. You must schedule downtime to restart the SQL Server (MSSQLSERVER) service to clear the memory fragmentation.

Step 4: Forcing Log Truncation and Fixing Log Chains

To fix failed to truncate sql logs veeam:

1. Verify the recovery model. In SSMS, right-click the database -> Properties -> Options. If it is Simple, configure Veeam's Guest Processing settings for this VM to "Perform copy only" or "Truncate logs" -> "No".
2. If it is Full and logs are not truncating, the chain is broken. You must take a native SQL Full Backup to reset the chain.
3. Open a New Query in SSMS and run a native backup to a null device to clear the pending log truncation: BACKUP DATABASE [YourDatabaseName] TO DISK = 'NUL' BACKUP LOG [YourDatabaseName] TO DISK = 'NUL'
4. Once complete, run the Veeam backup job again. It will now establish a new chain and truncate logs successfully.

Step 5: Mitigating Postgres Full Disk Space

If you hit postgres disk space full during a Veeam snapshot:

1. Increase the size of the volume holding /var/lib/pgsql/data/pg_wal (or wherever your WAL resides).
2. If you cannot increase disk size, you must speed up the Veeam backup. Ensure you are using HotAdd or Direct Storage Access rather than NBD (Network Block Device) mode.
3. Tune Postgres to allow WAL recycling by adjusting max_wal_size in postgresql.conf.

By following these diagnostic paths utilizing the Veeam Guest Helper logs, you can quickly identify whether your backup failure is a permission issue, a VSS writer failure, or a database configuration problem.