When looking at business continuity, it is crucial to have a well-designed backup strategy in order to make sure your data is fully protected. Whether you are on-premises or in the cloud, the idea is the same—keep regular backups of your data. This way, when disaster strikes, you will have something to fall back on.
But protecting your data is only half the battle, and the cost factor is not to be ignored either. That is why it is important to have a properly balanced and efficient backup plan that will make sure that you not only have your data regularly backed up, but also that this cost is kept at a reasonable level.
In this article we want to introduce you to one of the advanced, yet flexible backup strategies called Grandfather-Father-Son (GFS), and show you why you might want to consider it for your backup solution.
Backups and Retention Policies
Before we dig deeper into the details of Grandfather-Father-Son (GFS) backups, let us first consider retention policies in general, and why we need them in the first place.
As with any backups, you want to have the ability to go back in time and restore the data from a certain point. The more backups you have, the more points in time there are for you to fall back on if necessary. But the downside to this is that each backup consumes storage space, which translates to cost as well as additional overhead—you not only have to pay for the hardware and licensing, but you also have to consider the maintenance involved.
On the other hand, there are things that you have to consider, for example RPO (Recovery Point Objective)—the maximum period during which the data might be lost due to a major incident occurring—and your obligations to your clients for whom you might be storing the data. These clearly define the terms, which in turn, dictate the minimum amount of data that you have to store as your backups. For example, your company might not need to have it’s own daily backups kept for longer than a week, but you also could have a client who requires those backups to go much further back. So instead of keeping daily backups for days, it can be weeks or even months. The same applies for weekly, monthly, or any other backups that you might have.
Obviously it is necessary to find a balance, and the retention policies are there to do just that.
But what happens when you want to have everything optimized even further? When you are looking to have access to as many of your backups as possible, while at the same time keeping costs down?
If that’s the case, let’s see what the Grandfather-Father-Son (GFS) backup strategy can offer for you.
Grandfather-Father-Son (GFS) Backup Strategy
GFS is an advanced backup scheme that provides a great balance between cost and data retention, while at the same time allowing for a much desired flexibility. GFS consists of three (but more can be used if necessary) backup cycles, each with its own retention policy.
These cycles are usually something like daily, weekly, and monthly, but they can also be modified to fit your needs. So, for example, you might be required to keep data for five years. Well, you can have the yearly backups stored for five years, but also have monthly backups for 18 months, as well as daily backups for 120 days.
So what does this give you? It gives you lots of restore points to fall back on if something goes wrong within first 120 days (these would be the “son”—young backups), but what’s more you’ll have less of them, and you can only restore using monthly backups (the older “father” backups). When you go beyond 18 months, you only have yearly backups to rely on (the oldest “grandfather” backups).
What GFS actually allows you to do here is make great savings on storage space, while still giving you a reasonable amount of backups when you need them. No matter the use case you will very rarely have the need to actually store all your daily backups for years, and with multiple cycles that have their own retention periods, you will always have some room for optimization.
Grandfather-Father-Son and AWS
In the days before the cloud, storage was not only expensive, but it was very limited. The GFS scheme was one of those smart strategies that was there to save the precious resource of storage space.
Today thanks to AWS and other public cloud providers, it seems like anyone can get access to this infinite pool of resources with just a few clicks. But even though having unlimited storage sounds nice, you still have to pay for it—so GFS still have its uses even these days. On top of that, AWS comes with its own benefits, and utilizing the GFS strategy in the cloud can provide as much as it used to, if not more.
When working with AWS, a lot of the important data is stored on EBS volumes, which are backed up regularly using point in time snapshots—incremental backups of your data stored in S3. Having incremental backups of the data instead of full ones saves you a lot of space. But also, storing them in S3 provides incredible scalability and availability as well as durability (99.999999999%). S3 also comes with great security, and is compliant with PCI-DSS, HIPAA/HITECH, EU Data Protection Directive, and FISMA—to name just a few.
N2WS and GFS Backup Strategy
N2WS has come out with a great cloud-native backup tool, called N2WS Backup & Recovery, which was built specifically for AWS. This product gives you the ability to automatically back up your EC2 instances, but also restore them very quickly when a disaster occurs—within 30 seconds you can have your crucial workloads up and running not only in another region, but also on another AWS account if necessary.
With the 2.4 update, N2WS Backup & Recovery received some huge improvements, one of which is the ability to store your snapshots directly to S3 (for other new and enhanced features go here). Prior to this, storing snapshots was actually priced at $0.05 per GB, which was significantly higher than the regular cost of S3 ($0.023 per GB). Now you can make huge savings on snapshot storage, while still relying on all the benefits that S3 provides.
This also means that now you have even more room to maneuver when designing your GFS strategy. You can still use the same plan you had in place, but have the cost go down even more, or you could increase the retention for your policies, thereby gaining more backups and restore points, while spending the same amount of money as before.
Even though the Grandfather-Father-Son backup strategy originates from the old days of tape backups where a lack of resources was the primary issue, it still manages to find its use in the current days of cloud computing as a solution for cost optimization. Coupled with some modern tools and technologies, today GFS can actually provide even more than it used to in the past. So for those running AWS and in need of complex backup solutions, consider looking into GFS and N2WS Backup & Recovery to help you out.
- How to Copy EBS Snapshots to Amazon S3 and Save on Storage Costs
- Why EBS snapshots are not enough for AWS backup
- AWS Cost Optimization Guide