Hi all,
could someone help to find out what is causing this issue.
I have a third party backup solution (EMC Avamar) which uses in background Hyper-V VSS Writer to make backups.
Recently I've being getting problems that it couldn't make backup and there been found by EMC Support that periodically the Hyper-V Writer disappears from a list of VSS Writer:
vssadmin list writers
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2013 Microsoft Corp.
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: 'ASR Writer'
Writer Id: {be000cbe-11fe-4426-9c58-531aa6355fc4}
Writer Instance Id: {8529b1b6-4a8b-4e29-9719-c1004c02e0cb}
State: [1] Stable
Last error: No error
Writer name: 'Shadow Copy Optimization Writer'
Writer Id: {4dc3bdd4-ab48-4d07-adb0-3bee2926fd7f}
Writer Instance Id: {280e527f-5396-477d-8cb2-de110b6cbf41}
State: [1] Stable
Last error: No error
Writer name: 'Registry Writer'
Writer Id: {afbab4a2-367d-4d15-a586-71dbb18f8485}
Writer Instance Id: {ab9c692f-42a8-4d51-8708-57799a27210e}
State: [1] Stable
Last error: No error
Writer name: 'COM+ REGDB Writer'
Writer Id: {542da469-d3e1-473c-9f4f-7847f01fc64f}
Writer Instance Id: {71c2e39c-1bb8-4cbf-acaa-c5a54acc9de9}
State: [1] Stable
Last error: No error
and only after restarting VMMS Service I get it working (get-service vmms | restart-service):
vssadmin list writers
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2013 Microsoft Corp.
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: 'ASR Writer'
Writer Id: {be000cbe-11fe-4426-9c58-531aa6355fc4}
Writer Instance Id: {8529b1b6-4a8b-4e29-9719-c1004c02e0cb}
State: [1] Stable
Last error: No error
Writer name: 'Shadow Copy Optimization Writer'
Writer Id: {4dc3bdd4-ab48-4d07-adb0-3bee2926fd7f}
Writer Instance Id: {280e527f-5396-477d-8cb2-de110b6cbf41}
State: [1] Stable
Last error: No error
Writer name: 'Microsoft Hyper-V VSS Writer'
Writer Id: {66841cd4-6ded-4f4b-8f17-fd23f8ddc3de}
Writer Instance Id: {3b0e5883-1368-45e3-8cf0-a812016a437f}
State: [1] Stable
Last error: No error
Writer name: 'Registry Writer'
Writer Id: {afbab4a2-367d-4d15-a586-71dbb18f8485}
Writer Instance Id: {ab9c692f-42a8-4d51-8708-57799a27210e}
State: [1] Stable
Last error: No error
Writer name: 'COM+ REGDB Writer'
Writer Id: {542da469-d3e1-473c-9f4f-7847f01fc64f}
Writer Instance Id: {71c2e39c-1bb8-4cbf-acaa-c5a54acc9de9}
State: [1] Stable
Last error: No error
There are no suspicious EventLogs and I also have tried to completely disable Avamar Backup and anyway overnight it disappears.