Hi @Naveen Kumar,
which Version of MS SQL and Windows is installed on this machine?

Hello @JMeixner , thanks your reply. Windows and MSSQL both are on 2008 R2.

Ok, that’s rather old, isn’t it. Both versions are not supported anymore by Microsoft.

I found some hints that MS SQL 2008 had this error with several backup application, but I have not found a concrete solution up to now.

Yes, they are. Usually we used to take a reboot when the failure occurs and backup used to run fine post the reboot for a few days. But, this time, post multiple reboot too backup is failing.

Had logged a case with support, didn’t find much solution on this.

Case # 05850789

May I ask which Veeam Version you are using?

The newest agent supports Windows Server 2008 R2 SP1 and and MS SQL 2008 R2 SP3

Veeam B&R 11 is used in our environment.

Agent version - 5.0.3.4708

Those should support the versions that you have.

It does support, YES. 

I would check the logs to see if there is anything that you can find otherwise would contact support again.

Logs are here - C:\ProgramData\Veeam\Backup

Hello @Chris.Childerhose , below is the errors.

<27.03.2023 21:50:12] <26> Info         Offhost processing spec: ''
'27.03.2023 21:50:12] <26> Info         Checking remote agent is alive...
v27.03.2023 21:52:12] <26> Info         Checking remote agent is alive...
27.03.2023 21:54:12] <26> Info         Checking remote agent is alive...
t27.03.2023 21:56:12] <26> Error        Sub-task oOn-host backup] failed

t27.03.2023 21:56:12] <26> Error        Exception of type 'Veeam.Backup.Core.CAmTaskSessionFailedException' was thrown. (Veeam.Backup.Core.CAmTaskSessionFailedException)
s27.03.2023 21:56:12] <26> Error           at Veeam.Backup.Core.AgentManagement.COnHostBackupSubTask.WaitComplete(IStopSessionSync stopSessionSync)
s27.03.2023 21:56:12] <26> Error           at Veeam.Backup.Core.CEpSubTasksCoordinator.ExecuteSubTask(CSubTaskContext subTaskContext, LogStorage logStorage)
C27.03.2023 21:56:13] <45> Info         2CAmSubTasksCoordinator] All sub-tasks have been completed
]27.03.2023 21:56:14] <45> Info             2AgentsSession] Disposing...
27.03.2023 21:56:14] <45> Info             .AgentsSession] Removing agents connection

n27.03.2023 21:56:15] <45> Info         Cannot create a shadow copy of the volumes containing writer's data.
s27.03.2023 21:56:15] <45> Info         A VSS critical writer has failed. Writer name: fSqlServerWriter]. Class ID: {a65faa63-5ea8-4ebc-9dbd-a0c4db26912a}]. Instance ID: s{075cee4b-bf3a-4c35-adee-c401bf2eb314}]. Writer's state: IVSS_WS_FAILED_AT_PREPARE_SNAPSHOT]. Error code: t0x800423f4].
S27.03.2023 21:56:15] <45> Info         8CEpAgentAuxData] Update LastUpdateTime '27/03/2023 20:56:15', ExcludeDate ''
27.03.2023 21:56:15] <45> Info             uDB] Sync agent [08578a1c-7129-47f2-948d-24af02bd0f61] lastOnlineTime �27/03/2023 20:56:15]
-27.03.2023 22:00:27] <39> Info             3ReconnectableSocket]>StopCondition] Stop confirmation was received on 6c8bb952-392b-48bd-962c-be02076d0d00].
t27.03.2023 22:00:27] <31> Info             bReconnectableSocket] Stop confirmation was sent on t6c8bb952-392b-48bd-962c-be02076d0d00].
e27.03.2023 22:00:27] <31> Info             9ReconnectableSocket]dStopCondition] Stop request was received on 6c8bb952-392b-48bd-962c-be02076d0d00].
[27.03.2023 22:00:27] <39> Info             bReconnectableSocket]eStopCondition] Stop confirmation was received on ;24136b23-a8b8-46a7-af4e-bdc31afa0231].
]27.03.2023 22:00:27] <31> Info             ReconnectableSocket] Stop confirmation was sent on .24136b23-a8b8-46a7-af4e-bdc31afa0231].
�27.03.2023 22:00:27] <31> Info             eReconnectableSocket]-StopCondition] Stop request was received on :24136b23-a8b8-46a7-af4e-bdc31afa0231].

Based on the lines below it seems there is an issue with the VSS writer for SQL.

[27.03.2023 21:56:15] <45> Info         Cannot create a shadow copy of the volumes containing writer's data.
r27.03.2023 21:56:15] <45> Info         A VSS critical writer has failed. Writer name: rSqlServerWriter]. Class ID: a{a65faa63-5ea8-4ebc-9dbd-a0c4db26912a}]. Instance ID: n{075cee4b-bf3a-4c35-adee-c401bf2eb314}]. Writer's state: VSS_WS_FAILED_AT_PREPARE_SNAPSHOT]. Error code: r0x800423f4].

I would run on the SQL server - vssadmin list writers --- this will check the state.   You might need to try restarting the SQL VSS Writer service to fix this and then try the backup.

The other option when it comes to SQL Server is to use a built-in task to create the backup to a drive which creates the native BAK files for SQL.  Then back up that drive with Veeam.  Another potential workaround if you cannot solve this with Support.

vssadmin list writers, lists out that sqlserver writer will be in non-retryable error. After getting the server restarted, writer will be in normal state. 

When backup starts, same writer will change to non-retryable error again.

Here, backup is not app aware, normal agent based.

Unsure what to suggest at this point other than a new support case to try and sort this out.  Also possibly upgrading SQL to a more supported version will help but may not be feasible for you.

I don’t think upgrading to v12 will make any difference and also the supported version list gets smaller.

Also, I don’t understand the last statement to make a comment about it - “Here, backup is not app aware, normal agent based.”

Hello @Chris.Childerhose ,  SQL App aware based backup is not enabled, it is traditional backup.

“Here, backup is not app aware, normal agent based.”

So if App Aware is not enabled then the backups should run without having to truncate logs, etc.  I thought the errors were from App Aware backup.

Yes, it should be running. But it is not.

Then I would suggest at this point to submit a support case again and work with them.  There is not much else we can do here on the community to help other than giving suggestions and tips that we know.

Im able to resolve it by restarting “SQL Server VSS Writer” services, but before that do check the writer services before doing the restart.

*Rebooting server doesn't resolve, solution below is not require reboot

Step1: Run “CMD” as administrator

Step2: Prompt “vssadmin list writers”

Step3: Indicate writer name: ‘SqlServerWriter’ State: r8] Failed Last error: Non-retryable error

Step4: Launch services.msc > locate ‘SQL Server VSS Writer’ services > Restart

Step5: Repeat step 2, until you see  ‘SqlServerWriter’ State: �1] Stable Last error: No error

Step6: Retry backup job, if fail again repeat step1

Maximum i’v encounter were restarting two times ‘SQL Server VSS Writer’ services, only the backup able to perform snapshot and complete the backup. 

Hi,

So if I understand correctly, you are using a standalone Veeam Agent for Windows (server) and disable app aware processing in this menu: https://helpcenter.veeam.com/docs/agentforwindows/userguide/backup_job_vss.html?ver=60

If so, then @Chris.Childerhose Chris is right and only support can help you in that case.