VMware App Volumes – Tales of the missing Writable Volumes backup

15 Aug

You have a large VMware App Volumes environment and have backed up your writable volumes using the capabilities provided in the App Volumes Manager. (You are doing the right thing!)

AV Manager – WV Backup Config

We decided to perform an audit on the backup of the writable volumes within the App Volumes Manager 2.18.10 and the VSAN Datastore. You can export all the writable volumes to a CSV using the API. My script here will provide you with a complete outlook for conducting your analysis. Now exclude your group entitlements from the list, leaving you with the total number of writable volumes within your environment. Ideally, you are after the same number of writable volumes on the VSAN datastore. (Of course, if everything is going well in the backup world!)

In my case, we observed more than 300+ missing writable volumes between the exported CSV and the VSAN datastore. Let the investigations begin – within the production.log, we could see the backup was happening, but the challenge of a large environment is impossible to track all the backup occurring just by looking at the logs. Feature request to VMW – A dedicated backup log showcases the entire environment’s status. We eventually ended up with a GSS case after few months of back and forth and the logs exchange, we finally got a working solution. This closed the mystery of the missing backup of the writable volumes.

Solution

Go the the SQL database of the App Volumes Manager. Select the DB and New Query.

AV Database – Microsoft SQL

Enter the following query and hit execute. Now this will change the default writable volumes batch size(writables_backup_batch_size) from 5 to 25. Note the value of the batch size was tweaked multiple times, we first went with 10, which drastically reduced the missing backup. However, a few were still missing and not getting backup. The final number for our environment was 25 got all the writable volumes backup.

INSERT INTO dbo.settings ("key", value, created_at, updated_at) 
VALUES ('writables_backup_batch_size', 25, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)

Disclaimer – This tweak was required for a large App Volumes environment. Please consult with VMware Support before making any changes to your setup or Database. If it works for me doesn’t mean it will work for you. The value can differ based on the size of the enivronment.

I hope you will find this helpful information on your VMware App Volumes backup strategy. Please let me know if you have observed any issues like these, and would like to share your story?

Thanks,
Aresh Sarkari

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