윈도우 서버 백업 - Hyper-V 가상 머신이 백업되지 않는 경우
윈도우 서버 백업(wbadmin) 관리도구에서 마지막 백업 작업이 느낌표로 떴길래 확인해 보니 다음과 같이 VM 하나가 백업 과정에서 실패한 결과를 보이고 있습니다.
Writer Failures
Writer Id: {66841CD4-6DED-4F4B-8F17-FD23F8DDC3DE}
Instance Id: {86A24888-3A6D-4F81-A3A9-955863C02862}
Writer Name: Microsoft Hyper-V VSS Writer
Writer State: 5
Failure Result: 80042336
Application Result: 80004005
Application Message: (null)
Component: FD4BB964-2A7F-57EB-A692-54E56A798257
Logical Path: (null)
Component Result: 800423F4
Component Message: Could not create backup checkpoint for virtual machine '...': The shadow copy provider had an unexpected error while trying to process the specified operation. (0x8004230F). (Virtual machine ID FD4BB964-2A7F-57EB-A692-54E56A798257)
File Spec: D:\...\Virtual Machines\\FD4BB964-5A7F-47EB-A692-54E56A798257.xml Recursive: 0
File Spec: D:\...\\ddrive.vhdx Recursive: 0
File Spec: D:\....vhdx Recursive: 0
File Spec: D:\....vhdx Recursive: 0
File Spec: D:\...\Snapshots\\FD4BB964-2A7F-57EB-A692-54E56A798257-BackupSnapshot.xml Recursive: 0
File Spec: D:\...\\ddrive-AutoRecovery.avhdx Recursive: 0
File Spec: D:\...-AutoRecovery.avhdx Recursive: 0
File Spec: D:\...-AutoRecovery.avhdx Recursive: 0
*-----------------------------*
Application backup
Writer Id: {66841CD4-6DED-5F4B-8F17-FD23F8DDC3DE}
Component: FD4BB964-2A7F-57EB-A692-54E56A798257
Caption : Online\...
Logical Path:
Error : 80780175
Error Message : Component was skipped from volume shadow copy.
Detailed Error : 800423F4
Detailed Error Message : The writer experienced a non-transient error. If the backup process is retried,
the error is likely to reoccur
해당 VM에 로그인 해서 vssadmin 명령을 실행하면 Failed 상태의 VSS Writer 들이 있습니다.
C:\Windows\system32>vssadmin list writers
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2005 Microsoft Corp.
Waiting for responses.
These may be delayed if a shadow copy is being prepared.
Writer name: 'Task Scheduler Writer'
Writer Id: {d61d61c8-d73a-4eee-8cdd-f6f9786b7124}
Writer Instance Id: {1bddd48e-5052-49db-9b07-b96f96727e6b}
State: [1] Stable
Last error: No error
Writer name: 'VSS Metadata Store Writer'
Writer Id: {75dfb225-e2e4-4d39-9ac9-ffaff65ddf06}
Writer Instance Id: {088e7a7d-09a8-4cc6-a609-ad90e75ddc93}
State: [1] Stable
Last error: No error
Writer name: 'Performance Counters Writer'
Writer Id: {0bada1de-01a9-4625-8278-69e735f39dd2}
Writer Instance Id: {f0086dda-9efc-47c5-8eb6-a944c3d09381}
State: [1] Stable
Last error: No error
Writer name: 'System Writer'
Writer Id: {e8132975-6f93-4464-a53e-1050253ae220}
Writer Instance Id: {0ef4f237-484a-4cb9-98ae-d26968739abd}
State: [10] Failed
Last error: Timed out
Writer name: 'ASR Writer'
Writer Id: {be000cbe-11fe-4426-9c58-531aa6355fc4}
Writer Instance Id: {6c962330-ded8-4df8-b9bf-5515fc87dc3d}
State: [10] Failed
Last error: Timed out
Writer name: 'IIS Config Writer'
Writer Id: {2a40fd15-dfca-4aa8-a654-1f8c654603f6}
Writer Instance Id: {c758a808-113e-49fa-a736-1dbcc2329f5d}
State: [10] Failed
Last error: Timed out
Writer name: 'Registry Writer'
Writer Id: {afbab4a2-367d-4d15-a586-71dbb18f8485}
Writer Instance Id: {76bd1a4e-566c-4bbf-b69e-b9b99777c5cf}
State: [10] Failed
Last error: Timed out
Writer name: 'Shadow Copy Optimization Writer'
Writer Id: {4dc3bdd4-ab48-4d07-adb0-3bee2926fd7f}
Writer Instance Id: {89c9eac4-862c-4dc8-8ee4-738fa877376a}
State: [10] Failed
Last error: Timed out
Writer name: 'WMI Writer'
Writer Id: {a6ad56c2-b509-4e6c-bb19-49d8f43532f0}
Writer Instance Id: {9c71fb36-6727-4c8b-a80b-7045ab355e48}
State: [10] Failed
Last error: Timed out
Writer name: 'COM+ REGDB Writer'
Writer Id: {542da469-d3e1-473c-9f4f-7847f01fc64f}
Writer Instance Id: {c73dc37a-3e42-4db9-97cf-19eaaf7bd7cc}
State: [10] Failed
Last error: Timed out
검색해 보니 다음의 글이 나오는데요.
vssadmin list writers shows errors -> Windows Backup fails
; http://social.technet.microsoft.com/Forums/windowsserver/en-US/81b004bc-068c-4d13-aebb-d9477188fa9d/vssadmin-list-writers-shows-errors-windows-backup-fails?forum=winserverfiles
오호~~~ 실패한 VSS Writer와 연관된 서비스를 재시작하라는 것입니다. 그래서 가장 위에 있는 "System Writer"에 대해 "Cryptographic Services"를 재시작했더니 2개만 남고 해결되었습니다.
나머지 2개 중에서 "WMI Writer"의 경우 "Windows Management Instrumentation" 서비스를 재시작했더니 해결되었습니다.
그런데, 마지막까지 실패로 표시되어 있던 "IIS Config Writer"는 다릅니다. 얼핏 이름에서 "IIS"와 관련있는 듯 싶어 iisreset을 해도 해결되지 않았는데요. 다음의 글에서 그 해답을 발견할 수 있었습니다.
Documentation on restarting NPS and IIS Config writers in failed state
; http://social.technet.microsoft.com/Forums/windowsserver/en-US/65bc3fe7-4a0f-4c1d-ad37-004dbb9cd5e2/documentation-on-restarting-nps-and-iis-config-writers-in-failed-state?forum=windowsbackup
위의 글에 정리된 표를 보면 대응 관계가 이렇습니다.
| 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 |
| 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 |
| Registry Writer |
VSS |
Volume Shadow Copy |
| Shadow Copy Optimization Writer |
VSS |
Volume Shadow Copy |
| System Writer |
CryptSvc |
Cryptographic Services |
| WMI Writer |
Winmgmt |
Windows Management Instrumentation |
따라서, "Application Host Helper Service" 서비스를 재시작하고 나니 "IIS Config Writer"까지 모두 "Stable" 상태로 바뀌었습니다. 물론, 이 상태에서 다시 윈도우 서버 백업을 실행하니 정상적으로 처리가 되었습니다.
그러나 문제는? 애당초 VSS Writer들이 왜 이런 상태로 빠졌는지 알 수 없다는 것!
[이 글에 대해서 여러분들과 의견을 공유하고 싶습니다. 틀리거나 미흡한 부분 또는 의문 사항이 있으시면 언제든 댓글 남겨주십시오.]