There are a number of threats to your sensitive data: virus attacks, crashes, electricity or cooling failures and human mistakes. Backup is the option of the first choice to protect it. But it’s even more important how would your software restore the data from backup in case of disaster. Server downtime, overall RTO/RPO periods and backup consistency depends on a backup method. Whether you choose file system backup or imaging, it also matters where to put the data. Below we would explain specifics of Image-based backup to the cloud storage.
Technology Behind the Image-Based Backup to the Cloud
Traditionally backups were recorded on tapes or removable disks. Now they are being widely replaced by imaging software sending data to the cloud storage, because cloud storage services declare very high uptime. Modern backup solutions provide secure online backup to cloud storage services like Amazon S3, Microsoft Azure or Google Cloud Storage Nearline for Windows Desktops and Windows Server with MS SQL Server or MS Exchange Server.
Image-based backup tool makes a snapshot (an image) of the partition state at the specific point in time including operating system configuration, certain disk volumes, applications with their settings and file system. When the image is ready, the solution saves each partition as a single file and sends all files directly to the cloud avoiding interim storage. Now it’s ready for the recovery. In contrast with traditional backup methods it significantly speeds up backup data transfer, so you have full-blown backup ready to be retrieved as soon as the upload is done.
Block-level Incremental Backup to the Cloud
Image-based backup supports differential backup type allowing to perform full backup at the first time and then upload only changes in files or apps on a block-level. If some data was corrupted before subsequent backup, you can restore only those changes that were implemented earlier. User can go with versioning here, since it is a powerful feature that allows storing different versions of backup, decrease storage space and speed up the process.
Data Recovery From an Image
A typical recovery scenario is to restore an image file first and then perform a full system restore. Modern solutions though can backup and restore images directly to and from cloud avoiding intermediate caching.
As mentioned above recovery is even more important than backup. In case of disaster there are only two major questions that actually disturb a user:
- How long will it take to restore the whole system to its working state?
- Are there any data losses?
As a starting point for a robust and simple restore you should store backup image locally. As for a fully compliant disaster recovery scenario, cloud storage fits the best. Data restoration speed in this case doesn’t depend on software, but only on bandwidth throughput, so the overall downtime may take up to 4 – 7 hours. The size of an image also impact restoration time. It may vary from one operating system to another, for example the average image size for Windows Server 2012 R2 is approximately 32 GB.
The full system recovery could take a lot of time. If you don’t need to restore the whole machine, you can restore specific files and folders from a system image individually. This significantly simplifies the admin’s daily routine.
Disaster Recovery in the Cloud with Backup Software
Image of physical machine could be easily restored as a new virtual machine. It allows user to restore physical computer to VMware or Hyper-V without spending time on configurations. As an icing on the pie, modern software can restore an image directly to Amazon EC2 as an Amazon Machine Image and physical disk image could be restored as an Amazon EBS volume. These features allows developers and enterprises quickly migrate their apps or infrastructure to the cloud. And thus reduce downtime.
The bottom line is despite of initial image restore and backup can take lots of time, you don't have to worry about missing data. The technology behind cloud storage services is developing and allows to reduce server downtime and save money on hardware. That's why if you choose image based backup you should consider cloud storage as a reliable backup destination.
With so many advantages and the absence of critical flaws, image-based backup is worth testing.