Does it make sense to back up SQL Server databases locally in the cloud, particularly AWS?

"SQL Server Timeouts During Backups and CHECKDB" is an article on brentozar.com which points out the fact that virtual servers in the cloud use a single path to access both storage and network. That would mean bandwidth contention between storage reads (like from a backup process) and network access (Availability group network traffic) can cause query timeouts, availability group failovers etc.

A recent assignment saw me troubleshooting a backup process in AWS which involves all Diff/Tlog/Full backups for ~700GB of data being done locally, then being copied off to a domain controller via a Powershell script in Task Scheduler, every minute. It occurs to me that this involves dragging the backups across the same path to the network/storage twice.

Therefore running all backups to a UNC path seems like a no brainer in AWS EC2. Is that correct?

  • How would a UNC path help? That's still in and out across the network at the same time. – Michael - sqlbot Nov 9 '17 at 23:37
  • @Michael-sqlbot Because backing up locally involves yet another movement of data across the network, whereas backing up directly to the UNC path would involve a single movement of data across the network. – Peter Nov 10 '17 at 11:35
  • i.e.: Datafile on volume E: -> Backup to G: -> move to DC vs Datafile on volume E: -> Backup to DC. – Peter Nov 10 '17 at 11:41
  • I understand that part, but that isn't doing anything to relieve network contention during the backup itself -- it's only eliminating a second operation that occurs after the actual backup is already complete. – Michael - sqlbot Nov 10 '17 at 12:32

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.