Take the Technical Context into Account

Determine Storage Needs

You can’t hear it often enough: backup storage is a core component of any backup system. It must be properly sized, available, replicated—and above all, carefully planned.

If storage reaches capacity, backups can no longer run. If storage fails, backups stop. If a fire breaks out in the server room and backups are not replicated, backups are lost—and with them, the ability to recover data.

Fortunately, with proper planning, you can significantly reduce these risks—starting with avoiding poor storage sizing.

As a semi-industrial company, Coffecao generates large volumes of data. Much of it is critical, including legally required hygiene reports and measurement data from production equipment. But that’s not all.

Marketing data also consumes a significant amount of storage and is essential for customer acquisition. However, because it evolves slowly over time, it is generally classified as having normal criticality.

Even so, storage requirements remain substantial. Applying the backup policy means recalculating current needs while also anticipating future growth.

To identify storage needs, start by asking yourself the following questions:

• What type of data am I storing? Media files (images, audio, video) are far more space-consuming than text-based data.

• Does my data change over time? Or is it mostly static? This directly affects the size of incremental backups.

• How does storage usage evolve over time? Reviewing disk usage over recent months helps you anticipate future needs.

To optimize storage usage, technical solutions such as data compression can be used. Compression can significantly reduce disk usage but increases CPU load and backup duration.

Size Your Storage

As discussed earlier, you need to consider the following factors, adapted here to Coffecao’s environment:

• Total data volume

• Retention period for each criticality level

• Daily change rate

• Long-term archiving strategy

• Annual data growth rate

• Average compression ratio, if compression is enabled (which is not the case here)

The daily change rate corresponds to all data additions, deletions, and modifications that occur in a single day.

For example, on a file server over one day, you might observe:

• 1 GB of new files added

• 3 GB of files deleted

• 2 GB of files modified

The net growth is only 1 GB, but the total volume of changes is 6 GB.

Let’s apply these concepts to Coffecao.

With this information, we can estimate storage requirements. For simplicity, let’s assume all 100 GB of data is critical.

Based on this simplified estimate, Coffecao would need approximately 600 GB for backup storage and 800 GB for archive storage, with an expected annual growth of around 10%.

Over to You!

Context

You have assessed the criticality of EthicalIT’s various assets. Now it’s time to estimate long-term backup and archive storage needs.

You estimate a daily change rate of 5%, as the company operates primarily through services, and you plan to retain 1 annual, 4 quarterly, and 3 monthly backups.

After measuring approximately 892 MB on the company file server and adding 200 GB from critical servers (Active Directory, databases), you prepare a storage sizing estimate.

Instructions

Propose a total storage sizing—backup storage and archiving included—for EthicalIT’s environment.

Summary

• Storage is a critical component of the backup infrastructure.

• Storage sizing must account for multiple factors:

  • data volume;

  • average daily change rate;

  • short-term retention policy;

  • archiving strategy.

• The cost of storage and archiving should never be underestimated.

We’ve now covered storage in depth. Next, let’s explore the role backups play in an organization’s overall security.