Backup to Basics
As the image-based backup market progresses, everyone is pushing forward with trying to release the next big feature that will be the game changer. However, let's ground ourselves for a minute and go back to the basics. Here are the fundamental features that your backup software should come with, and you should be able to use right out of the box.
1. Restore a VM image as another name
I don't know about you, but when I was an admin and I had a report of corrupt data, I would NEVER remove the corrupt data for weeks after a restore was done. You never know if you can recover the data, or recover parts of the data that could apply to the restored data to create an even newer copy. With VM images, this is no different. Being able to restore a VM side by side with the corrupt VM provides the best chance to combine data from the newly restored VM and the corrupt one to ensure you have the most recent copy.
2. Skipped powered-off VMs
If you have powered off VMs in your production environment, these VMs are probably not that important, so let's have an option to skip backing up these VMs.
3. Turn off backup compression and encryption
Being able to turn off these two features is important for flexibility (see my previous post for a full explanation). Turning off these features allows you to work deduplication appliances to gain the best resulting backup time and footprint (typically resulting in backups that are 20 to 40 times smaller).
4. Mass-restore VMs in a single step
When you experience a disaster, such as a lost LUN, you want to be able to restore as many VMs at one time as possible with the least amount of work. Mass-restore capability allows you to restore an entire LUN of VMs rapidly to considerably boost administrator productivity when an outage like this occurs.
5. Mass-assign VM disks to a data store and virtual switch for recovery
When you need to recover an entire LUN of VMs it's beneficial to be able to quickly and easily assign all the same data stores and virtual switches to all the VMs being restored in a single job. In the same vein, you should also be able to split your disk assignments to different data stores if your VMs were backed up that way.
6. Skip deleted data on backup
Skipping deleted data is key for reducing the backup window, lowering your recovery time objective (RTO) and shrinking your overall backup footprint.
7. Resource controls for multi-threaded backups, restores
If you have large backup jobs with many VMs, or many backup jobs, it is good for your application to have control over how many backups are run at one time. This helps in several ways. Controlling the amount of resources consumed reduces the overall backup window. Applying controls also prevents excessive resource consumption and overwhelming the environment
8. Portable archives
Having archives per VM makes them portable, because you'll be able to copy a single VM to archive and keep it for recovery needs. This way you're able to copy off single VM archives off to any removable storage for recovery. Some products create a single large archive for the entire backup job, but over time these archives become so large, it's not practical to be able to move or copy them around.
9. Provide options for full, incremental and differential backup
The ability to pick how you want to do your backups is key to getting maximum efficiency and reliability in the backup process. The flexibility to use full, incremental and differential backups gives you the ability to tailor and optimize backup operations for different circumstances. For example, you might have a daily backup routine in which you run incrementals on a regular basis. But before the maintenance window, you could choose to execute a full new backup in order to feel comfortable that you have the latest version possible of your VMs.
10. Backup and restore at the same time
If you have a backup application it's important that it can let restores run while backups are running. Of course you would expect to be able to backup and restore at the same time, but not all products support this. Having a full, service-based architecture allows these functions to execute in parallel without disturbing one another.
The next time you're evaluating an image-based backup product, ask the vendor if its software provides features across all 10 considerations listed above, or at least how many of these their product addresses. By reviewing this list and, at a minimum, prioritizing the most important criteria for your circumstances, you will heighten your chances of selecting the right tools for your environment and ensure that you have the features you need when it matters most.
Posted by Jason Mattox on 07/15/2010 at 12:49 PM