MPX should not have any impact on VSS errors. VSS errors are generated from the client. One thought is that you may have multiple streams configured to run at the same time and, if allowed, you may be running into too many snaps at once or a capacity issue as another poster pointed out.

Easy way to check: disable MPX and run the backup by itself and see if you get the same error. Before doing this, you might take the opportunity to turn up the client logging so you can have info to look at if it fails again. Check the bpbkar and bpfis logs if it errors again. Don?t forget to set logging back to 0 when you?re done.

Thank you,

Rusty

From: veritas-bu-bounces AT mailman.eng.auburn DOT edu [mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of scott.george AT parker DOT com
Sent: Wednesday, March 21, 2012 7:15 AM
To: veritas-bu AT mailman.eng.auburn DOT edu
Subject: [Veritas-bu] Status 156 with multiplexing turned on

Greetings all,

I began using 2 STK T10000C drives in my SL8500.  Naturally, the bulk of my clients will not be able to push data to the capacity of the drive, so I have turned on multiplexing for certain policies and for the storage group itself.  I am running 6 jobs wide per drive, and seems to handle the throughput well.  

I am getting status 156 (snaphot error) on some SQL servers and am wondering if it is related to the multiplexing.  I know at its core it is related to VSS on the Windows server, but does multiplexing affect this in any way?

Your thoughts are greatly appreciated. "PLEASE NOTE: The preceding information may be confidential or privileged. It only should be used or disseminated for the purpose of conducting business with Parker. If you are not an intended recipient, please notify the sender by replying to this message and then delete the information from your system. Thank you for your cooperation."