Data ONTAP Discussions

SMSQL not providing application consistent snaps

We quite often have to mount copies of our production SQL cluster to our UAT and development environments. The process is straightforward: Create a SMSQL snapshot, create a flexclone using that snapshot as the base, present the cloned luns to the UAT/DEV servers and mount the database.

Usually this works just as expected and the databases can attach to the server without any issues. However a couple of times, upon attaching the database to the SQL server we see the following:

Msg 1813, Level 16, State 2, Line 2

Could not open new database '**DBNAME**'. CREATE DATABASE is aborted.

Msg 3437, Level 21, State 3, Line 2

An error occurred while recovering database '**DBNAME**'. Unable to connect to Microsoft Distributed Transaction Coordinator (MS DTC) to check the completion status of transaction (0:761111491). Fix MS DTC, and run recovery again.

For our UAT environment this is not an issue, we can simply create another snapshot and try again. What concerns me is that this has happened on our nightly backups and in a disaster event, there's a possibility SMSQL has not created an application consistent snapshot which we then are unable to use for disaster recovery.

Has anyone ever encountered this before?

All servers are SnapManager for SQL 5.1, Windows 2008 R2 SP1  and SQL 2008.



Re: SMSQL not providing application consistent snaps

Just had this happen again.. unable to attach a database from a snapshot and the same MS DTC error logged in event viewer. Obviously very rare as the original post was 3 months ago but it seems there are instances where SMSQL does not always provide consistent snaps.

The DTC error is misleading, have spent a lot of time investigating that to no avail.

Re: SMSQL not providing application consistent snaps


Quick question on this one - have the snapshot in question been verified during backup with a positive result?


Re: SMSQL not providing application consistent snaps

In the first instance back in December, yes it was verified. 11pm backup, verified overnight and snap then mounted to a remote server at 9am the following day.

This most recent time was without verification. We take hourly snapshots for mounting to a reporting server so verification would take too long as we need the data for reporting asap. This will possibly be replaced by SMSQL Clone Database functionality eventually.