Was recently working with a client working on backup and came across this error

Shared Search Index

Completed

11/19/2008 2:04 PM

Object Shared Search Index failed in event OnPrepareBackup. For more information, see the error log located in the backup directory. UnauthorizedAccessException: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))

 

With some more troubleshooting i came to this error in the trace logs on the index server which indicates backup is not the culprit but something to do with Search or the SSP not having the right permissions

11/19/2008 13:56:47.31 w3wp.exe (0x119C)                                0x0D78 Search Server Common              MS Search Administration               86z4     High      Exception caught in Search Admin web-service (server). System.UnauthorizedAccessException: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))     at Microsoft.Office.Server.Search.Administration.SearchApi.RunOnServer[T](CodeToRun`1 remoteCode, CodeToRun`1 localCode, Boolean useCurrentSecurityContext, Int32 versionIn)    

I was able to get around this by giving the SSP Service Account/App Pool admin permissions on the index server.  I’m sure it was a more granular permission that could have fixed this issue but i didn’t have the time to troubleshoot this issue and the SSP Service Account is not externally exposed so our exposure is limited.