Microsoft Virtualization Discussions

SMHV backup causes "device not ready for access yet" errors in Windows system event log



I have a 3-node Windows Server 2008 R2 SP1 cluster, connected to FAS2040 filer. Cluster is using CSV disks and runs Hyper-V. All cluster nodes have SnapMirror 6.3.1R1, and SnapManager for HyperV 1.0 installed. One cluster node has 3 VM clients, owns all associated CSVs, and runs SMHV job. 

The issue we are seeing is that every time SMHV scheduled backup executes, we get a flood of about 40-50 events in Windows event log on the cluster node that runs the job:

Log Name:      System

Source:        Disk

Date:          3/23/2012 6:11:42 PM

Event ID:      15

Task Category: None

Level:         Error

Keywords:      Classic

User:          N/A

Computer:      bma-vhost-03


The device, \Device\Harddisk16\DR242, is not ready for access yet.

This flood comes in 4 bursts, presumably one burst per each CSV that is being snapshot as part of the backup.

This does not seem to affect anything negatively - cluster is healthy, VM clients are happy, and we have not heard of any complaints from the users of the virtual servers. But it is creating a management headache - we need to be aware of these disk events as they generally speaking are early warnings of imminent problems. As a result our monitoring systems go off every time this backup is executed. 

Is there a solution to this event log chatter issue?





is this a question your team can handle or should this be asked in the NetApp Support Community ?



Looks like you were not able to help on this issue here.  We have external and internal subject matter experts in the NetApp Support Community answering questions about SnapX products and software.  If you have a NOW login, this link enables you to engage them about this.



Thanks Mike, i'll try to post as you suggested.


Hi Dennis,

Do you have ONTAP DSM and Windows host utilities kit installed on the systems?



Hello Santhosh

Yes i have ontap dsm and the kit installed as well, DSM version is 3.5.45484.1225, kit version is 6.0.4108.1216.


Hi Dennis,

We are experiencing the same issues.

Have you been able to solve the problem? Have you gotten a reasonable answer from NetApp?

I would very much appreciate if you would share the solution.




We have seen the same issue and were advised that when netbackup is running, NBU calls the ontap VSS, creates a snapshot and subsequent clone which windows then tries to mount. As it is a foreign disk the mount fails and the error is generated. We have then updated the NBU client to only use the MS VSS provider but we still see the same issue although the corresponding lun enumeration errors are no longer generated.

Any additional suggestions here would be most appreciated.