File opening throws RBS exception after migrating to a new farm with sql 2012

Question

We have successfully migrated the SP 2010 -sql 2008 r2 wss_content to a new sp2010 farm with sql 2012. The old and new farms are configured for RBS - FIlestream.
In the new farm when tried opening a document we see the below exceptions in event viewer. The documents open fine for admin users and fail for others. I have verified all the permissions on the blob store file location and it looks good. Users have no 
issue uploading new files over and below the set the file size limit.
Any suggestions on how to debug this would be great, do we need to rerun the .migrate() to realign any of the blob file references, we played around setting the max file size couple of times.
Event vwr on DB server -
FILESTREAM file named with GUID '00311100-0000-51eb-f3a8-0b387bc5c5ce' that belongs to FILESTREAM data file ID 0x10001 does not exist or cannot be opened.
Event vwr on Front end -
Message ID:20, Level:ERR , Process:10580, Thread:36
Blob store <FilestreamProvider_1> threw this exception:
Operation: Unknown
BlobStoreId: 1
Log Time: 5/5/2014 8:00:49 PM
Exception: Microsoft.Data.SqlRemoteBlobs.BlobStoreException: There was a generic database error. For more information, see the included exception. ---> System.Data.SqlClient.SqlException: A transport-level error has occurred when receiving results from
the server. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)
   at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)
   at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
   at System.Data.SqlClient.TdsParserStateObject.ReadSniError(TdsParserStateObject stateObj, UInt32 error)
   at System.Data.SqlClient.TdsParserStateObject.ReadSni(DbAsyncResult asyncResult, TdsParserStateObject stateObj)
   at System.Data.SqlClient.TdsParserStateObject.ReadNetworkPacket()
   at System.Data.SqlClient.TdsParserStateObject.ReadBuffer()
   at System.Data.SqlClient.TdsParserStateObject.ReadByteArray(Byte[] buff, Int32 offset, Int32 len)
   at System.Data.SqlClient.TdsParserStateObject.ReadInt64()
   at System.Data.SqlClient.TdsParserStateObject.ReadPlpLength(Boolean returnPlpNullIfNull)
   at System.Data.SqlClient.TdsParser.ProcessColumnHeader(SqlMetaDataPriv col, TdsParserStateObject stateObj, Boolean& isNull)
   at System.Data.SqlClient.SqlDataReader.ReadColumnHeader(Int32 i)
   at System.Data.SqlClient.SqlDataReader.GetBytesInternal(Int32 i, Int64 dataIndex, Byte[] buffer, Int32 bufferIndex, Int32 length)
   at System.Data.SqlClient.SqlDataReader.GetBytes(Int32 i, Int64 dataIndex, Byte[] buffer, Int32 bufferIndex, Int32 length)
   at Microsoft.Data.BlobStores.FilestreamBlobStore.FilestreamStoreLibraryBase.ReadBlob(Byte[] storePoolId, Byte[] storeBlobId)
   --- End of inner exception stack trace ---
   at Microsoft.Data.BlobStores.FilestreamBlobStore.FilestreamStoreLibraryBase.ReadBlob(Byte[] storePoolId, Byte[] storeBlobId)
   at Microsoft.Data.BlobStores.BlobStore.ReadBlobInternal(Request request)
BlobStoreException Code: OperationFailedAuthoritative
-Mash "http://sharepointxperiments.wordpress.com"

Answer 1

Migration - its a content db backup/restore/mount to new farm with sql 2012 from sql 2008 r2
Okie here are the results after we tried to narrow down the issue to few steps-
This issue happens on documents that are already existed in the content db prior to migration. we picked two docs from one library. DOC A and DOC B of close to same size..
DOC A - file size 64k, rbs max size set to 1mb.
Regular User and SPAdmin both can open fine, check out n check in successfully.
no entries made in event vwr of front end and DB server
DOC B - file size 64k, rbs max size set to 1mb
SPAdmin - can check out n open fine, but cannot check in back - file not available error
Regular User - cannot open the file - file not avialable at the url
          Both users can view doc properties at lib level..
Errors found in event vwr of DB server -
"FILESTREAM file named with GUID '00311100-0000-51eb-f3a8-0b387bc5c5ce' that belongs to
FILESTREAM data file ID 0x10001 does not exist or cannot be opened."    
and
       "The operating system returned the error '2(The system cannot find the file specified.)' while attempting 'FsDoHandler::CreateFile' on 'H:\Blob_Store\a06953ae-6f49-43b1-9c2d-fefb13bda9fe\1c581a4a-b450-4143-bc3d-8d419b49b0fb\0000eb20-000066ff-0002'
at 'fstrman.cpp'(2075)."
I incline to believe that the references for documents in blob store could have been corrupted for some documents during the migration. Any new docs uploaded to content or to blob are all accessible fine.
I'm not sure running .migrate() will re align the blob file references? Any ideas on how to effectively get this resolved..
-Mash "http://sharepointxperiments.wordpress.com"