DPM Backup of CSV storage on Equallogic

Addendum: Essentially I am looking for best practise from Dell as to the configuration in this scenario.

You can run DPM w/o the EQL HW provider.    Typically this condition is caused because, with the EQL HW provider installed VSS creates a snapshot on the array instead of the unused local disk space on the volume being backedup.  However, DPM, won't log into that snapshot so it can't "see" the snapshot the VSS references.

The one benefit of a HW provider is that up to 3 backups can run at once, with the default SW provider only one can.

Here's a list of some common fixes that are needed to get DPM to work better.

A virtual machine online backup fails in Windows Server 2008 R2 when the SAN policy is set to "Offline All"

support.microsoft.com/.../2521348

Unable to backup Live Virtual Machines in Server 2008 R2 Hyper-V

support.microsoft.com/.../2004712

On a Microsoft Windows Server 2008 R2 Fail over cluster with a Hyper-V guest with many pass-through disks, the machine configuration may take some time to come online

support.microsoft.com/.../2020559

Computer randomly stops responding after you use the VSS software provider in Windows Server 2008 R2 or in Windows 7

support.microsoft.com/.../2627052

CSV LUNs fail if you use a VSS hardware provider to back up virtual machines on a Windows Server 2008 R2-based cluster

support.microsoft.com/.../2637197

The Cluster service stops responding if you run backup applications in parallel in Windows Server 2008 R2

support.microsoft.com/.../2277439

MPIO does not log path failure events in the event log on a Windows Server 2008 R2-based computer

support.microsoft.com/.../2670762

MPIO does not remove a disk that is on a failed path in Windows Server 2008 R2

support.microsoft.com/.../2661794

The iSCSI initiator may show a incorrect MPIO path state

support.microsoft.com/.../2387367

Some I/O requests to a storage device fail on a fault-tolerant system that is running Windows Server 2008 or Windows Server 2008 R2 when you perform a surprise removal of one path to the storage device

support.microsoft.com/.../2406705

The TCP Chimney Offload feature fails on all network adapters in Windows Server 2008 R2 or in Windows 7 if you disable or change the properties of a network adapter

support.microsoft.com/.../2477730

The Microsoft iSCSI Initiator may fail to login to Favorite Targets after the Initiator Name is changed on Windows Server 2008 and 2008 R2 or Windows 7

support.microsoft.com/.../2500271

Description of the hotfix rollup package for System Center Data Protection Manager 2010: March 2011

support.microsoft.com/.../2465832

Description of hotfix rollup package 6 for System Center Data Protection Manager 2010: July 2012

support.microsoft.com/.../2718797

Description of Update Rollup 2 for System Center 2012

support.microsoft.com/.../2706783

DPM protection agent service may stop responding on Exchange Server 2010 servers that are protected by System Center DPM 2010

support.microsoft.com/.../2664761

System Center Data Protection Manager 2010 Hyper-V protection: Configuring cluster networks for CSV redirected access

support.microsoft.com/.../2473194

Assuming you checked the usual (switch configuration, iSCSI disk timeout values), you should open a support case.  We can then look at the ASM logs to see what else might be causing this.

The iSCSI disk timeout setting are in a document called “iSCSI Initiator and Operating System Considerations” located on the same page of the Firmware download you currently have installed on your arrays.

The switch configuration’s are listed here: en.community.dell.com/.../3615.rapid-equallogic-configuration-portal-by-sis.aspx

The most important part of the switch configuration is to enable flow control, and Jumbo (if the switch can support both, if no flow control is the most important).

You should also review the "Cconfiguration guide" (look for the link at the top of the page, a lot of good info here): en.community.dell.com/.../2632.storage-infrastructure-and-solutions-team-publications.aspx

Regarding the writer, it’s not recommended to disable the eqlvss writer if using ASM.  I’m not certin,but I believe you end up with a “Unsupported VSS application writer” icon and warning in ASM.

Regarding best practices, these are listed in “TR1045-Microsoft Hyper-V ProtectionUsingASMME_ISO.pdf” located on the support site (support.equallogic.com) and “TR1043-HyperV-PSSeriesArray_BP_2.0.pdf” (just go to the Resources> Tech Report Section and do a page search for “hyper” you should see both documents under the Microsoft Windows section – they are named slightly different in the list though, the first one is “Microsoft Hyper-V Protection Using Auto-Snapshot Manager/Microsoft Edition” and “Deploying Microsoft Hyper-V with PS Series Arrays”)

You didn’t mention the backup software you are using.

Also, post the FW version and the HIT version you have installed.

-joe

Hi Don,

With regard to this section:

    "You can run DPM w/o the EQL HW provider. Typically this condition is caused because, with the EQL HW provider installed VSS creates a snapshot on the array instead of the unused local disk space on the volume being backedup.  However, DPM, won't log into that snapshot so it can't "see" the snapshot the VSS references."

My Question:

Do you know how I can get DPM to read into the VSS snap on the array. Is it as simple as configuring a network interface on the DPM server (I.e. a DPM backup network) that can access the iSCSI network or will I still have issues with CHAP authentication for the target LUN's?

Thanks

Danny

Thanks Joe,

The backup software we're using is DPM (Microsoft's Data Protection Manager 2010). We're not using the ASM features on the array unless this is used by Performance or Capacity load balancing - but I can't see reference to this in documentation.

The easiest path is for me to disable the eqlvss writer on the Hyper-V nodes and I've asked Don a question below about how to enable DPM to hook into the target LUN where the snapshot would be stored when using the Equallogic VSS writer.

Regards

Danny

If you get an answer back, please let us know.   That would be a fantastic addon.   Such off host are faster and put allot less stress on network and servers.  

Thanks.

Thanks Don,

I work regularly with the DPM team at Microsoft and will request an enhancement and see where it goes.

Thanks again.

Danny