Yellow Bricks

by Duncan Epping

BC-DR

VCB and Diskeeper

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I just noticed this new KB article:

Diskeeper is a 3rd party defragmentation product that has the ability to defragment unmounted NTFS volumes that are presented to the VMware Consolidated Backup proxy. This means that it can defragment RDM LUNs. Unfortunately, this creates the possibility of inconsistencies in the file system if there is a virtual machine running on that RDM.

The Automatic Defragment option causes the defragmentation to take place.

Consult your Diskeeper documentation to obtain instructions for disabling this feature in the version of the product that is installed on the VCB Proxy server.

Be aware to not use Diskeeper on your VCB proxy!

VMware vCenter Data Recovery

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During VMworld I quickly wrote down the steps that VMware vCenter Data Recovery takes when backing up VMs. I added one step which isn’t unimportant, changed block tracking(4):

  1. Create a snapshot of disk(s)
  2. Hot add disk(s) to Data Recovery appliance
  3. Create hashes of (hopefully variable) blocks
  4. Read data of changed blocks if previous backup exists
  5. Dedupe(using variable chunk sizes) and create SHA1 hash for index
  6. Store data (possibly encrypted)
  7. Remove hot add disk(s)
  8. Remove snapshot

Compared to the current VCB installable and current feature set VI 3.5 offers this is a huge enhancement. (VMware vCenter Data Recovery will be part of the vSphere products.) Creating deduplicated back ups of only the changed blocks based on variable chunk sizes will give every user the opportunity to have a decent backup scheme. VMware vCenter Data Recovery utilizes the new VMware Consolidated Backup API by the way. For those afraid that the dedupe datastore gets corrupted an automated short integrity check is performed once a day and a thorough integrity check once a week.

Keep in mind that not only VMware will be able to utilize these new features. Because VCB is changed to an API a much tighter integration with 3rd party backup tools can be expected in the near future!

I would love to get my hands on a beta version of the product as soon as it’s available to play around with it some more and tell you more about the rich feature set this product will have. Unfortunately it’s not available yet and you will all have to wait, but I will keep you posted.

SRM Patch released

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VMware just released patch 2 for SRM 1.0 Update 1. It’s a cumulative patch that corrects several problems with 1.o Update 1:

  • a problem that prevents protected virtual machines from following recommended Distributed Resource Scheduler (DRS) settings when recovering to more than one DRS cluster.
  • a problem observed at sites that support more than seven ESX hosts. If you refresh inventory mappings when connected to such a site, the display becomes unresponsive for up to ten minutes. (This problem was also addressed in Patch 1 for SRM 1.0 Update 1.)

Before you apply the patch please backup both SRM server’s / databases.

EMC adds automated failback to SRM

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EMC just announced that they are adding automated failbacks to SRM for their Celerra family via a vCenter plugin. I hope I can see a demo here at VMworld:

VMware Site Recovery Manager Automated Failback via a VMware vCenter plug-in helps Celerra customers coordinate a “failback” to the original virtual infrastructure, including all the process steps once VMware Site Recovery Manager performs a failover. EMC offers the only solution on the market today that arms customers with end-to-end disaster recovery at the simple push of a button.

SRM and rescanning your storage twice

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I just got off the phone with a former colleague. He was implementing SRM at a customer site and couldn’t get it working correctly because the VMFS volumes weren’t discovered at the recovery site. As most of you know sometimes you need to rescan your HBA’s twice before the LUNs and orVMFS volumes are discovered. When using SRM the rescan only occurs once by default. Fortunately this is a setting that can be changed in the vmware-dr.xml file:

To enable the additional rescan, edit the vmware-dr.xml file at both the protected and recovery sites to add a <hostRescanRepeatCnt> element within the <SanProvider> element. Set the value of <hostRescanRepeatCnt> to 2, as shown in the following example:
<SanProvider>
.
.
.
<hostRescanRepeatCnt>2</hostRescanRepeatCnt>
</SanProvider>

If you are doing SRM implementations it might be useful to write this one down… Especially when combined with HP EVA’s.