SqlServerWriter

We have a third party tool Unitrends to backup VM ware (snapshot), we see some backup errors in SQL log, this is mentioned in this thread, http://social.technet.microsoft.com/Forums/en-US/sqldatabaseengine/thread/f80e8d43-f0b4-4663-88da-902a23977a94.

Our network person contacts Unitrends and they said it is because our SQLServerWriter is broken.

I have a couple of questions,

 first, we don't want it to backup databases, but just backup filesystem or snapshot, does that use this service?

Also when I do the VSSAdmin list writers, I got

Writer name: 'SqlServerWriter'
   Writer Id: {a65faa63-5ea8-4ebc-9dbd-a0c4db26912a}
   Writer Instance Id: {cc18327c-615f-429b-ad99-16cdc1caa8ea}
   State: [8] Failed
   Last error: Non-retryable error

Is there a way I can test on the SQL server to see if the SQLServerWriter is broker or not?

Thanks

SQLFriend