Avamar – How to exclude the Windows folder WinSxS from the File System backup

Article Number: 517188Article Version: 3 Article Type: How To

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The WinSxS folder is a system folder that stores different copies of DLLs and system files and can significantly grow in size with time.

As a system folder, it is not recommended to exclude it, specially from the VSS backup, because that will affect future disaster recoveries that could end up in data loss.

But if the WinSxS has to be excluded by all means, perhaps because the WinSxS is causing some issues in the client machine, it cannot be achieved via flags in avtar.cmd, nor editing the dataset.

The only way of excluding the WinSxS folder is via registry:

1) Export the registry key ( to be used as a backup ):


2) Add new Multi-String value under HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlBackupRestoreFilesNotToBackup

Name: WinSxS

Value: %windir%WinSxS*.* /s

3) There is no need to reboot the machine afterwards.

NOTE: More information here.


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