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Image backup causing SQL client disconnect
Does anyone have experience with VM image backups that invoke the Microsoft VSS writers on a guest client running MS SQL Server, cause the SQL clients to time out or disconnect during the remove or revert snapshot at the end of the backup?
Several of our applications that use a continuous SQL client connection lose their connection to the SQL database right at the end of the image backup of the SQL server. The base requirement is that the SQL server's operating system be recoverable from the image backup. We assume the underlying VSS snapshot is required to guarantee the image is recoverable. The SQL database backups are run separately using the MSSQL tools, and don't seem to cause problems.
If anyone knows a way to exclude the VSS SQL writer from the list of writers that run snapshots during a backup, it would be helpful.
ionthegeek
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September 19th, 2013 06:00
VMware Tools is responsible for invoking the VSS writers during VMware snapshots. There's a VMware KB that covers how to exclude specific VSS writers from being invoked:
VMware KB: Disabling specific VSS writers with VMware Tools
admingineerchitact
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September 19th, 2013 18:00
Wow! I've been looking for that for 10 years! You don't happen to know if a similar exclusion concept is available for physical servers, do you?
ionthegeek
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September 20th, 2013 06:00
For physical systems, as far as I know there's no official way to exclude specific VSS writers.
After searching around a bit, I found some hints on Technet that disabling the SQL VSS Writer Service will prevent the SQL writer from being invoked. If you're using Avamar for the physical server backups, you could probably write a prescript that calls "net stop" to stop the SQL VSS Writer Service and a postscript that calls "net start" to start it back up again. It's hacky but it might do what you need.
Edit: Clarity