Implementing a floating CommServe name for faster DR recovery

UPDATE: As of v11 SP11 this method is not supported on the CommServe due to possible communication issues. I’ll leave the post up for reference and will update when an alternative method is available.

In the event of losing your primary CommServe (CS) you’ll need to restore your database to the DR CS. This is a simple enough process involving the following (high level) steps:

  1. Ensure your DR CS is installed and at the same patch level as your current (now unavailable) CS.
  2. Restore the latest DR database dump to the DR CommServe using CSRecoveryAssistant.exe
  3. Use the Name Management Wizard to update all clients & MediaAgents to use the DR CS name.

This works well in most scenarios; however, if you are keen to get the process finished as quickly as possible Step 3 can take some time. Books Online advises that it can take “30 seconds per online physical client and 20 seconds per offline physical client”. If you have 1000’s of clients, this can be a long time to wait. It is for this reason that changing the CS name on the clients ahead of time (during a defined outage window) can save precious time during an actual disaster.

Official documentation for this procedure can be found here. This document aims to achieve the CommCell rename without the requirement to rename the host name of the CommServe computer. In this example I’ll be renaming cs01.test.local to commserve.mydomain.com, allowing a common name for both internal and external backup clients.

The steps below assume you already have a working single CommServe (no SQL cluster) environment. Before making any changes you should:

  1. Ensure all clients (MediaAgents included) are referencing the CommServe by DNS name, not IP.
  2. Create a CNAME in your internal (end external if appropriate) DNS services.
  3. Stop all jobs
  4. Disable the scheduler
  5. Perform a DR backup
  6. Ensure there is no current DDB activity on the MediaAgents (Check SIDBEngine.log on the MediaAgents)

Before starting, the properties page of your CommCell should display your current actual CommCell host name.

Before-Name

Open a command prompt and navigate to the base directory. Login with the qlogin command.

qlogin

Run the following command (adjusting instance & the two names as appropriate):

SetPreImagedNames.exe CSNAME -instance Instance001 -hostname yournewfloatingname.com youroldfullqualifiedname.local -skipODBC

setpreimagednames

Close the Commcell properties (if it was still open) and reopen it. You should see the new floating name reflected on the General tab:

After-Name

Next Step is to update the clients to reference the new name. Restart the Commcell console GUI then open the Commvault Control Panel and select Name Management. Select “Update CommServe for Clients (use this option after DR restore)” and click Next. Ensure the New CommServe name matches your desired FQDN and click Next.

NameManagement1

Move all clients requiring the updated name across, be sure to leave the checkbox unchecked.

NameManagement2

Some clients may have issues updating, these will need to be investigated individually. Try restarting the services and check client readiness from the CommCell Console. In the case of the PC below it was the Firewall at fault (revealed with help from CVInstallMgr.log).

FailedCLients

Check the client properties (you’ll need to refresh the client list first using F5) and you should see that the CommServe hostname has been updated to reflect the new FQDN.

complete

Once all clients are pointing to the new CNAME, you can simply update DNS rather that using name management during a DR failover.

 

 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s