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Sep 21 2009

VMware Data Recovery step-by-step for newbie’s

Firstly I have to say that this post was born due to my frustration with VMware Data Recovery. I was lucky or unlucky enough to be target by few different bugs in all releases, up to 1.0.2.

VDR promises to deliver virtual machine disk-to-disk backup and recovery solution with integrated de-duplication that was before only found in expensive enterprise class products.

I use VDR as a backup solution for VMs that do not require more than a backup per month (Operational System, Application Binaries, etc…). Critical application data is backed up by the enterprise class backup system. VMware clearly states that VDR is not a replacement for VCP (VMware Consolidated Backup) or your traditional backup tool.

My intent here is to go through the steps from configuration to limitations, issues and troubleshooting. There is a large collection of documents on the net so the objective here is to put together a key research index for newbie’s. I’m not going to re-invent the wheel when someone else already did all the work.

Installation
This always the easy part when talking about VMware products. The virtual appliance is imported from a OVF and with some basic configuration is ready to begin backups.  An IP must be configured and a VMDK must be added to the virtual appliance as a target for the de-duplicated data.

@vladan did a great job recording VDR installation process
http://www.youtube.com/watch?v=ZtxGa2rb78A (Part 1)
http://www.youtube.com/watch?v=kAB9iTXJ1Pg (Part 2)
http://www.youtube.com/watch?v=3qjprEjKXBc (Part 3)

Two good Step-by-Step posts about deployment from @ccostan
How to install the VMware Data Recovery Appliance (vDR)
Configuring a Network share for VMware Data Recovery (vDR)

I use a NFS/CIFS enabled SAN so it was easy to decide what path to take to store backups and the de-duplication store. If you are not as fortunate you may consider using one of your old servers running OpenFiller or FreeNAS.

VMware highly recommends that you use virtual disks (VMDKs) or RDMs for dedupe stores since the performance behavior is well-understood and consistent. More info at http://viops.vmware.com/home/docs/DOC-1551


How it Works

“Unlike VMware Consolidated Backup (VCB), which is an enabling technology and not an actual data backup product, VMware Data Recovery is a standalone product that creates hot backups of virtual machines to any virtual disk storage attached to an ESX/ESXi host, or to any NFS/CIFS network storage server or device and is not meant as a replacement for VMware Consolidated Backup.”

VDR was built using the VMware vStorage APIs for Data Protection (VADP) and implements a Virtual Appliance (CentOS) and a VI Client Plugin. The deduplication method used is VMDK block based instead of file based. I am not a storage guy so I might be wrong here but I don’t see how block level deduplication could provide in anyway benefits comparable to file level dedup.

What VMware decided to implement for VDR dedupe is (take a deep breath) – block based in-line destination deduplication.  Deconstructing it means the following:

1. We discover data commonality at the disk block level as oppose to the file level.
2. It is done as we stream the backup data to the destination disk as opposed to a post-backup process.
3. The actual dedupe process occurs as we store the data on the destination disk as opposed to when we are scanning the source VM’s virtual disks prior to the backup.

We chose this dedupe architecture because it fit best with what we were trying to achieve with VDR and what the vSphere platform provided to us. What were these reasons? Stay tuned to this space……

The following two posts from VMware employee Azmir Mohamed will provide you with more in-depth technical details on block based in-line destination deduplication technology.

VMware’s Backup and Recovery product
VMware Data Recovery Taking Advantage of vSphere 4

Limitations

  1. VDR will not backup virtual machines with Fault Tolerance enabled
  2. VDR does not support VC Linked mode
  3. Virtual Machines with hardware version lower than 7 will take longer to be backed up.
  4. The deduplication feature cannot be disabled so all backups done by VDR are deduplicated
  5. Not compatible with VI3 hosts. VDR requires the presence of a VMware vCenter Server 4
  6. VDR will not backup your VM if it is stored in a RDM not in virtual compatibility mode
  7. VDR is available only for Essentials Plus, Advanced, Enterprise and Enterprise Plus
  8. Each VDR appliance supports only 100 virtual machines

If you know additional limitations let me know and I will include here.

  • Issues and Troubleshooting
    I had few issues with VDR plug-in not being able to communicate to the appliance and also with CIFS shares.  As a result I had to re-deploy the appliance and reconfigure the network a number of times. Few of those times I was forced to delete the de-duplication store.

    Even the recently baked 1.0.2 release presented similar bugs. Luckily the VMware community is always very involved and help us  to find the solutions.

    Potential VDR+CIFS Workaround

    Snapshot issues have also been identified. In short – VDR leave hidden snapshots behind during the backup process. You will find more information on Scott Lowe’s and Carlos Costanzo blogs.


    Summary

    As mentioned before VDR is still it’s early versions. VDR is a good step for VMware promising to deliver recovery solutions aligned with de-duplication before only found in expensive enterprise class products. However the product is not mature enough and should not be used as the only backup solution.

    I’m still using VDR as a backup solution for VMs and VMDKs that does not require more than one backup per month (Operational System, Application Binaries, golden image etc…). The application data is backed up by our enterprise class backup system.

    Useful Documentation
    VMware Data Recovery 1.0.2 Release Notes
    http://www.vmware.com/support/vdr/doc/vdr_102_releasenotes.html

    VMware Data Recovery Documentation
    http://www.vmware.com/support/pubs/vdr_pubs.html

  • VMware Data Recovery FAQ
    http://www.vmware.com/files/pdf/VMware_Data_Recovery_FAQ_4.21.09.pdf
  • VMware Data Recovery Dedupe Store Setup Guideline
    http://viops.vmware.com/home/docs/DOC-1551
  • File Level Restore Usage
    http://communities.vmware.com/docs/DOC-10670
  • 2 comments

    1. data recovery NYC

      hi
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    2. Recovering VMware Data

      Thanks for sharing such an informative post… Excellent information about VMware data recovery process

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