Amazon EC2 backup options and differences

2
votes

I have an EC2 Instance running Windows Server 2012. My server is running a MySQL database, a wordpress website, and a Web Service, all in IIS. I installed these manually and configured them myself if that's important.

I looked into methods for backing up, and came across EBS Snapshots (Elastic Block Store > Snapshots > Create Snapshot), and Images (Instances > Actions > Image > Create Image). From my understanding, an EBS Snapshot is a snapshot (backup) of any attached EBS volumes (in my case the root drive C). An Image is an image of the entire instance. Am I correct so far in my descriptions of the two methods?

I want to have a backup of my server as described above (database, wordpress, web service, iis settings). Would am EBS Snapshot suffice for this? i.e, if my instance or ebs volume fails one day, by recreating an instance and attaching the EBS snapshot to the new instance, will my server be configured the same as the failed instance (database, wordpress, web service, iis settings, etc)?

I am assuming an Image restore to a new instance will mean absolutely everything will be restored as on the initial instance correct?

So with all that said, would an EBS snapshot be enough as a backup solution?

1
mysqlwordpressiisamazon-ec2

1 Answers

1
votes

An EBS Snapshot is a crash consistent backup of your volume. By crash consistent it means that it is as good as if your machine crashed (for example, you unplug your computer). It means that open files that have pending changes in buffers might not had been persisted to disk.

So it is not an application consistent backup such as those that can be done with applications that support VSS snapshots, but probably it will be good enough for basic disaster recovery.

Here you will find more info about crash consistent and application consistent backups.

Another important caveat is that for Windows instances, you want to create your AMIs by using Instances > Actions > Image > Create Image. If you try to create a Windows AMI from a volume, it will default to Linux and you won't be able to use them as an AMI to reinstantiate your Windows Server.