Tape Backup Rotation and Replacement — How Often Should You Do It?

Tape Backup Rotation and Replacement — How Often Should You Do It?

The list of top 10 largest corporations in the world by market cap is dominated by tech companies that hold an enormous quantity of consumer information and business data. Apple. Microsoft. Alphabet/Google. Amazon. Meta/Facebook. Tencent. Closer home, think about your own dependence on data and the crippling blow a catastrophic data loss would deal to your business. Backups are therefore essential.

A catastrophic data loss could deal your business a crippling blow

Many small and medium-sized businesses (SMBs) opt for tape backups. Tapes have a large capacity, a long, stable shelf, and are inexpensive. If you opt for tape backups, you need a strategy for tape rotation and tape retirement/replacement. Tape rotation ensures backups remain current and available and that the most accurate recovery possible is achieved. It protects tapes from excessive wear as well.

There are different tape rotation strategies whose suitability depends on your business needs as well as regulatory requirements. Over time, you may have to change or customize your tape rotation strategy in line with evolving goals. So, let’s take a look at the strategies. 

  1. Single Tape

This is the lowest cost but least sophisticated and highest risk rotation strategy. Using one tape for repeated backups is better than no backup at all. You use the same tape daily and then replace it when it shows signs of failure. Note that a single tape here (and the rest of this writeup) does not necessarily mean one tape but the set of tapes required for a single backup. Sometimes, that could be two or more tapes.

Single tape backup is fairly common in many small businesses. The main drawback is that if anything happens to the tape, you have nothing to fall back on. And with the high frequency of use, the chances of tape failure are certainly higher than with other strategies.

  1. Round Robin

The Round Robin technique will typically have a tape for each day of the week. These are used in succession, so the same tape is used for every day of the week. You can make this rotation strategy more resilient by designating more than one tape for a particular day of the week (usually Friday). The two tapes for that one day would then be rotated offsite each week.

A Round Robin backup will usually involve running a full backup on a daily basis. This should not be an issue if you own a micro or small business. It could however be tedious for medium-sized and large organizations that have a lot of data that would require a considerable time to complete a full backup.

  1. GFS

GFS stands for Grandfather-Father-Son. This rotation technique adds an extra layer of complexity to the Round Robin method but still retains a degree of straightforwardness that most people won’t have a problem understanding. Still, GFS is not a monolith. There are different ways to apply it which would require anywhere between 8 and 22 tapes assuming a 5-day work week.

The most common GFS version involves first making daily incremental backups from Monday to Thursday. These are the ‘sons’. You then run a full backup each Friday which is deemed the ‘father’. At month’s end, make another full backup and store offsite. This is the ‘grandfather’. Variation of GFS versions will come down to how long you want the backups preserved. 

  1. Tower of Hanoi

Named after a 19th-century puzzle highlighting the power of combinatorial explosion, this is the most complex rotation strategy. The complexity makes it hard to track and is prone to mishaps if done manually. Adding an extra tape to the Tower of Hanoi formation doubles the rotation time frame. It is a good option when you are looking to keep backups for a long time without using a high number of tapes. 

Using ten tapes would see your oldest backup be three years old

For example, in a four tape rotation, tape 1 is used every other day, tape 2 is used on alternate days, tape 3 alternates with the tape 1+2 cycle then tape 4 runs once you complete a tape 1+2+3 cycle. So for four tapes, the rotation is as follows: 1-2-1-3-1-2-1-4-1-2-1-3-1-2-1-4. To understand the compounding effect, using ten tapes would see your oldest backup be three years old when a cycle is complete.

Wrapping Up

Despite rotation, tapes can and will fail. Prepare for this by defining your tape retirement and replacement schedule based on the manufacturer-recommended service life. However, your tapes may age quicker than expected. So keep an eye on rewrite errors and other early signs of impending tape failure. A tape that increasingly runs into errors should be replaced at the earliest opportunity. 

While tape backups are fairly reliable and affordable, cloud backups are a better alternative most times. Also known as remote or online backups, your data is sent to a secondary location in the cloud typically hosted by a 3rd party. Cloud backup is easier to automate, accessible from anywhere and is non-affected by on-premises disruptions and disasters. As a SaaS product, the cost is within reach of SMBs.

Don’t leave your data to chance. B-Comp Services can help your business define and deploy the most suitable backup strategy. Call 303-282-4934 or contact us for a consultation.