Disk-Only Backups vs. Tape Backups: Mitigating the Risk of Hacker Attacks

Companies today face a critical decision when it comes to data backup and storage. Disk-only backups offer convenience and accessibility but carry a higher risk of vulnerability to cyber attacks. This article explores the potential risks associated with conducting disk-only backups and provides insights into a balanced approach combining disk and tape backups to mitigate these risks.

The Risks of Disk-Only Backups

While disk-only backups offer immediate access and flexibility, they are not without their vulnerabilities. In a recent project, we encountered a significant challenge when a major company had to isolate their production lines from the main business operations. Any interaction with the data, whether live or backup, required physical access to a secure location next to the production line. While this method is effective, many companies find it impractical or overly restrictive.

The primary concern with disk-only backups is the increased risk of data breaches due to their accessibility. A single successful cyberattack could render a company's entire data repository useless. Hackers can exploit vulnerabilities in the storage infrastructure, potentially leading to the complete destruction of the data.

Why Tape Backup is Still Important

For companies that find the physical isolation method too restrictive or impractical, tape backup offers a secure and cost-effective alternative. Tape provides a physical layer of security that makes it significantly more difficult for unauthorized personnel to access the backed-up data. Even in the face of determined cyberattacks, the chances of tape being compromised are lower. Additionally, the use of tape backup reduces the risk of data loss due to environmental factors, such as heat and power outages, which can render disks unreadable.

Cost Considerations

While disk-only backups may seem more convenient, they come with higher costs that can be a significant burden for companies storing data for long-term retention. According to several independent analysts, the cost of disk-to-disk backup—even with deduplication—can be 7 to 1 or even more times higher than backup to tape. This expense is driven by several factors:

Data Center Floor Space: Tape can store more terabytes of data in a single square meter of data center space compared to disk. Acquisition Cost: More terabytes of tape can be purchased for the same budget compared to disk. Power and Cooling: Once written, tape requires minimal HVAC controls, while disk storage needs to be kept powered on. Unpowered disks can suffer from common failure modes such as stiction and bit rot, leading to potential data loss after a few months or a year.

Compared to disk storage, which generates heat during operation, tape storage is more energy-efficient and cost-effective over the long term.

Best Practices for Data Protection

Best practices recommend a balanced approach to backup and storage. Here are some key recommendations:

Day-to-Day Disk Backups: Use disk-to-disk backups for daily data captures. This ensures that data can be quickly restored when needed. Replication to a Second Site: Replicate necessary data to a second site for disaster recovery purposes. This creates a redundant copy of your data in a different location. Tape Copies for Archive and Audit: Regularly copy necessary data to tape as a second off-site copy for archive and audit purposes. This provides an additional layer of security and ensures data integrity over the long term.

This hybrid approach allows companies to maintain a reasonable amount of data on disk for fast restores while leveraging tape for long-term storage and security. For example, you might retain data on disk for 30 to 180 days, using tape for archival and audit purposes.

Overall, while disk-only backups offer convenience, integrating disk and tape backups offers a robust and secure solution. Companies should carefully consider the risks and benefits of each method to ensure the highest level of data protection.