There’s been a debate for many years in IT circles over which backup technology is better. But rather than waste time entering the debate, let’s focus on your organisation’s specific needs and requirements, and what you hope to achieve with your current budget.
Choosing your backup solution is no easy task. You’ll need to consider certain backup metrics, identify your storage requirements and work within your organisation’s budget. Before making your mind up, look at how quickly you need your data back in the event of a failure, how long you need to keep it for and how much you're willing to spend.
You’re then capable of making an informed decision regarding the best backup solution for your business. The options available include tape, disk and hybrid solutions:
- Tape backup systems: Tape backup uses a wide tape wound around a spool inside a cartridge. The tape is inserted into a backup drive and data is written on it.
- Disk-based backup systems: A complete snapshot of your computer is taken and written to a file on a hard disk. A snapshot is a copy of your entire system, including files, settings, operating system, programs and application data as an image. In a disk to disk to disk (D2D2D) solution, you have hard drives onsite as well as offsite or in the cloud, so if local backup fails, your systems won’t fail.
- Hybrid backup systems (D2D2T): This offers the best of both solutions. An image backup or snapshot is created to disk, then backed up to tape.
Each solution comes with its own set of benefits and challenges. Therefore, you need to tailor your backup system to your organisation's needs and requirements.
Here are three steps to help you get started:
1. Establish RPO And RTO Metrics
When you’re choosing a backup solution, consider what you need recovered and how quickly you want it restored. Recovery Point Objective (RPO) refers to the frequency of backup, while Recovery Time Objective (RTO) relates to your downtime.
Senior Systems Engineer Ryan Tucker summarises the metrics like this:
“How much are you willing to lose, and how long are you willing to wait for the backup to restore?”
Think about the degree of activity in your IT system to determine your RPO. For example, if data is constantly swapping and changing, you may need hourly backups. In order to establish your RTO, look at the cost of downtime to your business. For example, if you’re an online organisation, your short RTO requires you to invest in a backup solution with swift restore times.
When it comes to single-file restores, disk backups recover faster because data is retrieved through random access, whereas a tape has a sequential access method.
“Tape is linear. Inside is a big spool of tape, and data is written sequentially on the tape. If you want to recover a file, it has to spool or wind forward to that part of the tape to recover the file” - Senior Consultant Mike Brown
“Disk-based backup systems can provide greater RPOs through the use of image/block-based incrementals and faster RTOs due to the backups being stored on or near line, avoiding the delays associated with physical retrieval and inventory tapes” - Tucker.
In order to identify your RPO and RTO, establish how often your data changes and how badly your business would be affected by downtime. When you have these metrics, it will narrow down prospective solutions for your business.
2. Look At Your Storage Requirements
Is all your data disposable after a certain date, or would you like to preserve it indefinitely? Reflect on whether you need short-term or long-term storage, as this will help determine the necessary solution.
Because contemporary tape technology boasts a shelf life of up to 30 years, it’s superior to long term storage, or archiving. In contrast, hard drives last between three and five years, and are less shock resistant because of their moving parts.
“Electronic mechanisms fail over time. Hard drives contain many moving parts like heads and spindles, which can fail quickly. Tape backup has fewer moving parts and lends itself to more copies of your data, which reduces your risk.” - Brown
If you want to archive your databut you still want rapid restore times, you have the option of blending the two types of backup. This allows you to capitalise on the faster restore times of disk while archiving to tape at a slower pace.
Conversely, if your storage requirements are short-term and you want rapid restores, you might benefit most from disk backup systems. You’ve also got the option of spending slightly more on a D2D2D solution with onsite and offsite backups so if your primary hard drives fail, you can still continue business as usual.
The key is to stop focusing on the abstracted weaknesses and strengths of each piece of hardware. Instead, look at the type of solution that gives you the desired restore times and suits your storage requirements.
3. Consider Your Budget
Now that you've determined your backup metrics and storage requirements, you can addprice to the equation. Look at the cost of the backup solution against the context of your organisation's data security requirements.
Mike sheds some light on approximate up-front costs for SMBs, remembering there will be variances in relation to your organisation’s requirements. These prices include the cost of hardware, software and labour.
- Tape: $4000 - $6000. This is a great solution if you want to archive your data and rapid system restores aren’t a priority.
- Disk to disk: under $2000. Disk-based systems are recommended for rapid restores. Spending slightly more on a D2D2D means if your local backup fails, you will lose your data. Therefore, when using disk-to-disk, you need to be vigilant with monitoring, maintenance and testing.
- Disk to disk to disk (D2D2D): $4000 - $6000. Disks are usually faster at recovering your entire system . However, keep in mind that if you have backed up to the cloud, your restore time will depend on the speed of your Internet connection. The bonus of D2D2D is if your local backup fails, you’ll still have your offsite backups to keep you going.
- Hybrid (D2D2T): $9000. Disk utilises the advantages of both disk and tape, ensuring a fast online backup of your live system followed by a slower backup to tape. You gain the robustness of tape as an offsite medium, but maintain the fast restore times of disk.
Before you decide to go with what looks like the cheapest option, remember to consider hidden costs. These include anything from the cost of administration, maintenance and support, or the cost of upgrades. For example, increasing the depth capacity of tape backups just means purchasing additional cartridges, while a disk system upgrade may require a new controller, power supply and disks.
Therefore, before investing in a particular option, you need to consider what you are paying for and why. Save yourself a lot of strife and don’t let price dictate your decision. Tailor the solution to your backup metrics and storage requirements to get the best from your backup system.
Choosing a Backup Solution
If you take anything away from this chapter, take away the fact the ideal backup system can only be determined in the context of your RPO and RTO metrics, storage requirements and budget. Determine your business requirements, and look at price against the backdrop of the investment in your organisation’s future. Before committing to a particular vendor or solution, consult with your internal IT staff and external specialists to get a tailored backup solution for your organisation.
Related: How to manage a backup solution