HOWTO: Use Site Recovery Manager and Linked Clones together

Customers dig Site Recovery Manager – simple, easy, integrated Disaster Recovery for VMware (and more on SRM very, very soon).

Customer dig VMware View Composer – a simple elegant way to reduce storage costs associated with VDI deployments.

One thing that sucks is that they don’t work out of the box together.   After an SRM failover, the relationships between the base replicas and the linked clones are broken.

VMware and EMC collaborated on a project recently with a customer, and that project included documenting the detail on why this occurs, and also the workaround.

If you’re interested – read on!

The key is that the ADAM and View SQL databases actually store the vCenter instance name (in the form of a Moref ID – also known as the MOID), which after SRM failover has changed, which breaks the replica/linked clone relationship.  Further, the parent location is explicitly in the vmdk descriptor.

You can (without doing anything fancy), you can deploy new desktop pools, but can’t access existing linked clones, or recompose or refresh. 

Here’s what you have on Site A (the protected site in SRM nomenclature)

This is what you have after SRM failover on Site B (recovery site in SRM nomenclature):

 

The workaround is simple.

update the ADAM and View SQL databases to have the correct, updated MOID.   This was shown to add only a few minutes to an SRM recovery plan, and in fact, could be added to the SRM plan itself as a callout script.

The results of the whole proof of concept were shown at VMworld 2009 in session DV2181 (thank you Tommy Walker, Stephen Spellicy, Suresh Thoppay, Brian Johnson).

You can download the whitepaper with details here (publicly, on EMC.com).

The script and details are posted on Powerlink for EMCers, VMware folks, and EMC partners (where we will maintain/update it) along with other solutions support collateral for services engagements with customers – you can find them using this Powerlink path:

Home > Solutions > Horizontal Solutions > Selling into VMware Environments > Solution Areas > View (VDI) > Product Specific Kit > Celerra

Note that while it shows as Celerra-specific, this technique will work with any VMFS datastore (and in fact, should work with NFS datastores after SRM 4 is released)

I’ve attached the script itself for public use here.  Note that like all scripts, this doesn’t come with any guarantees, and certainly not formal support, though if delivered through a service engagement, becomes officially supported.

Understanding the script:

• VM.cmd

This script is to change the IP address and set the DNS server IP addresses. The script is stored on vCenter server and is referenced in the SRM recovery steps. It requires two parameters (VM Name and VM IP address). If using just Windows 2003, changing the IP address can be performed using customization instead of this script in the recovery step.

Note: Need to have Powershell installed on VM to run.

• SetIP.ps1

The supporting file for VM.cmd. vSphere PowerCLI should be installed on the vCenter server and Powershell installed on the VM. Need to update the script with proper DNS IP addresses for that site and the ESX server & VM authentication information.

• Updvmdk.cmd

This script is used to launch the bash script on the ESX server. This script uses plink.exe which is part of Putty application suite. This script is used in SRM recovery step to fix the path of replica vmdk. The script resides on vCenter server.

• Updvmdk.sh

This script is the supporting file for Updvmdk.cmd. This file resides on the same folder as updvmdk.cmd

• UpdDNS.cmd

This script is executed in the recovery step before running the Syncdb.cmd. This script updates the vCenter alias and updates the DNS A record that users use to connect to the view manager.

• SyncDB.cmd

This script is executed in the recovery step after recovering View Manager VMs and View Composer database recovery and vCenter DNS alias update.

• SyncDB.PS1

This file is supporting file for SyncDB.cmd. The script uses Quest Active roles management shell for Active directory. This script resides on vCenter. If need to have the SRM test functionality, this script can be moved inside any virtual machine that has access to a domain controller, Primary View Manager and View Composer database virtual machine.

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