Summary
There are instances when block-level backup fail because the VSS writers are in a failed state, but it is impossible or not desirable to restart the server until at least after business hours.
Symptoms
VSS writers in a failed state cause block-level backup failures.
Block level backup fails with the following errors:
X.X.X.X sssnap Mon Feb 18 15:04:23 2019 SNBSNP3069E 4680: MsSnapShot::check_wrts_report_okay::check_wrt_status rc[-1]
X.X.X.X sssnap Mon Feb 18 15:04:23 2019 SNBSNP3069E 4680: Failed to check the status of all writers after snapshot rc [-1]
X.X.X.X sssnap Mon Feb 18 15:04:24 2019 SNBSNP3069E 4680: BACKUP::backup_components failed rc(-10)
X.X.X.X sssnap Mon Feb 18 15:04:24 2019 SNBSNP3069E 4680: Failed to backup the applications / disk ( RC(-16)
X.X.X.X aph Mon Feb 18 15:04:24 2019 SNBAPH_381E Exception in message (BACKUP_VSS) to module (sssnap), reqrc (-16)
Resolution
VSS writers are application-specific components for Microsoft's Volume Shadow Copy Service (not operating system dependent), which ensure the consistency of application data when a shadow copy is created, and are useful for creating consistent backups of a system. However, some of these writers enter error states more or less frequently. An alternative solution other than restarting the server is to restart each of the associated services for each of the VSS writers in a failed state by following the steps below:
- Find each of the VSS writers in a failed state by issuing this command in an elevated command prompt:
- vssadmin list writers
- Make a list of all the failed VSS writers, or take a screenshot.
- Find the VSS writer's associated Service Display Name in the table below and restart the service.
- Issue the command again to confirm the status has changed to Stable with no Error:
- vssadmin list writers
- Attempt to perform another block-level backup
- If the VSS writers fail again, you must restart the server.
| VSS Writer | Service Name | Service Display Name |
|---|---|---|
| ASR Writer | VSS | Volume Shadow Copy |
| BITS Writer | BITS | Background Intelligent Transfer Service |
| COM+ REGDB Writer | VSS | Volume Shadow Copy |
| DFS Replication service writer | DFSR | DFS Replication |
| DHCP Jet Writer | DHCPServer | DHCP Server |
| FRS Writer | NtFrs | File Replication |
| FSRM writer | srmsvc | File Server Resource Manager |
| IIS Config Writer | AppHostSvc | Application Host Helper Service |
| IIS Metabase Writer | IISADMIN | IIS Admin Service |
| Microsoft Exchange Writer | MSExchangeIS | Microsoft Exchange Information Store |
| Microsoft Hyper-V VSS Writer | vmms | Hyper-V Virtual Machine Management |
| NTDS | NTDS | Active Directory Domain Services |
| OSearch VSS Writer | OSearch | Office SharePoint Server Search |
| OSearch14 VSS Writer | OSearch14 | SharePoint Server Search 14 |
| Registry Writer | VSS | Volume Shadow Copy |
| Shadow Copy Optimization Writer | VSS | Volume Shadow Copy |
| SPSearch VSS Writer | SPSearch | Windows SharePoint Services Search |
| SPSearch4 VSS Writer | SPSearch4 | SharePoint Foundation Search V4 |
| SqlServerWriter | SQLWriter | SQL Server VSS Writer |
| System Writer | CryptSvc | Cryptographic Services |
| TermServLicensing | TermServLicensing | Remote Desktop Licensing |
| WINS Jet Writer | WINS | Windows Internet Name Service (WINS) |
| WMI Writer | Winmgmt | Windows Management Instrumentation |