Backups are obviously an important part of any managed infrastructure deployment. Computing systems are inherently fallible, through operator error or hardware failure. Existing systems must be backed up, from configurations, software and media files, to the backend data store.
In a managed hosting environment or cloud hosting environment, it is convenient to use various filesystem snapshot technologies to perform backups of entire disk volumes in one go. These are powerful, fast, reliable, and easy to execute. In Amazon EC2 for example these EBS snapshots are stored on S3. But what happens if your data center goes down – through network outage or power failure? Or further what happens if S3 goes offline? Similar failures can affect traditional managed hosting facilities as well.
This is where offsite backups come in handy. You would the be able to rebuild your application stack and infrastructure despite your entire production servers being offline. That’s peace of mind! Offsite backups can come in many different flavors:
- mysqldump of the entire database, performed daily and copied to alternate hosting facility
- semi-synchronous replication slave to alternate datacenter or region
- DRBD setup – distributed filesystem upon which your database runs
- replicated copy of version control repository – housing software, documentation & configurations
Offsite backups can also be coupled with a frequent sync of the binlog files (transaction logs). These in combination with your full database dump will allow you to perform point-in-time recovery to the exact point the outage began, further reducing potential data loss.