With so many users new to Azure, Sometimes an issue appears more complex than it really is.
If you back up your databases to Azure blob storage but your company uses proxy servers for internet access, you will need to configure backuptoURL.exe.config per SQL Server Backup to URL Best Practices and Troubleshooting.
We had a customer who called us for help because their backup to URL no longer worked after they implemented proxy server for their organization. They continued to face issues even after they configured backuptoURL.exe.config file.
This is the error they received:
A nonrecoverable I/O error occurred on file "https://<storage acct name>.blob.core.windows.net/container1/<dbname>_backup_2016_09_29_105902.bak:" Backup to URL received an exception from the remote endpoint. Exception Message: Unable to connect to the remote server.
Customer also pointed out that using azCopy, he was able to copy files from the SQL machine to the same blob storage. The account used to do azCopy was different from the SQL Server startup account. So we had customer start SQL Server with the account used for azCopy. Then the backup url was successful.
It turned out that they didn’t configure proxy setting for the service account (they only configured proxy setting for the interactive user) to point to the proxy server. After logging onto the SQL machine with the service account and configuring the proxy setting via IE, then their backup started to work with the service account.
Below are the a couple of screenshots on how you configure proxy server for an individual users
Jack Li |Senior Escalation Engineer | Microsoft SQL Server