What is the rule of thumb backup?

A rule of thumb backup refers to an established simplified guideline or principle regarding the practice of regularly backing up computer data. Having a consistent and reliable backup process in place is critical for protecting important files and information in case of system failure, data corruption, cyber attacks, or other catastrophic events.

Backups serve as a crucial safeguard that enables the restoration of lost or damaged data. Without proper backups, companies and individuals risk permanently losing valuable documents, photos, financial records, and other digital assets. A rule of thumb backup strategy lays out straightforward best practices so that even non-technical users can easily implement a backup routine to safeguard irreplaceable data.


The origins of the term “rule of thumb” in relation to backups can be traced back to the early days of personal computing and data storage. As hard drives became more common in home computers in the 1980s and 1990s, it became important for users to make copies of their data in case of hardware failure or accidental deletion. Technology journalists and computer experts began advising users to follow a “rule of thumb” and back up their data regularly.

One of the earliest references to this rule of thumb came from technology journalist John C. Dvorak in 1984, who wrote “A good rule of thumb is to back up (copy) everything whenever you feel the data is becoming important or hard to recreate” (https://www.reddit.com/r/ProgrammerHumor/comments/uqwia1/true_story/). This simple advice highlighted the need for average computer users, not just experts, to regularly backup their data for protection.

Over the years, variations on the “rule of thumb” backup emerged, suggesting different frequencies and methods. But the underlying advice remained to consistently backup important computer data to prevent permanent loss. The rule of thumb endured as a commonsense approach to data protection accessible to non-expert users.


Backups are critical for protecting against data loss. According to the US Geological Survey, “Backups protect against human errors, hardware failure, virus attacks, power outages, and natural disasters.” Without backups, important data could be permanently lost if anything happens to the original copy. Backups provide a way to restore data if it becomes corrupted, deleted, or otherwise inaccessible.

Regular backups make recovering from data loss events much easier. According to NetApp, “Backup and recovery is the process of creating and storing copies of data that can be used to protect organizations against data loss.” Backups give you multiple copies spread across different media, so if one copy is impacted, you can restore from another. The purpose of backups is having redundancy to mitigate risk and ensure business continuity if disaster strikes.

3-2-1 Rule

The 3-2-1 rule is a best practice for backup strategies that recommends having at least 3 total copies of your data, stored on 2 different media types, with at least 1 copy stored offsite. This rule helps protect against data loss from hardware failure, accidental deletion, file corruption, ransomware, natural disasters, and other threats.

The key components of the 3-2-1 rule are:

  • 3 copies total – Having at least 3 total copies means that if one copy becomes unavailable or corrupted, you still have two more copies to restore from.
  • 2 different media types – Storing copies on different media spreads out risk. For example, you could have 1 copy on a hard drive, 1 copy on a USB drive, and 1 cloud backup.
  • 1 copy offsite – Keeping 1 copy offsite (e.g. cloud storage) protects against site disasters like fires or floods destroying any onsite backups.

The 3-2-1 rule originated in photography for protecting photo archives, but is now considered a best practice for any data backup strategy. It provides a simple model for resilient backup with redundancy to protect against different risks. Key industry sources recommend the 3-2-1 rule as a baseline for backup protection (TechTarget, 2022).

Types of Backups

There are a few main types of backups to consider:“Types of backup explained: Full, incremental, differential, etc.”[1]

Full vs Incremental Backups

A full backup copies all the data in the files that are selected to be backed up. This produces a complete copy of the backed up data as it existed at the time of the backup. Full backups take longer to complete and require more storage space than incremental backups, but allow for faster and simpler restores since all the required data is stored in one backup file.“Types of Backup: Full, Differential, and Incremental”[2]

An incremental backup only copies data that has changed since the last backup. This makes incremental backups faster to complete and requires less storage space. However, to fully restore data from incremental backups, you need the most recent full backup as well as every incremental backup done since then. Incremental backups are useful for frequent backups of data that changes often.“Types of Backup: Full, Incremental, and Differential”[3]

Disk Image vs File Backups

A disk image backup makes an exact copy of an entire disk partition or storage volume. This backup contains not just files, but also the filesystem, boot records, partition table, and operating system. Disk images allow for easy full system restores but require large amounts of storage space.

A file backup copies only the specific files and folders selected by the user. This allows for more customized backups focused on important data. File backups require less storage space but do not contain system settings, programs, or operating system files needed for full system restores.

Backup Software

There are many backup software options available, with both paid and free solutions. Some leading options include:

Acronis Cyber Protect Home Office – Offers full image and file backups, ransomware protection, and easy restoration. However, it can be resource intensive during backups.

Veeam Agent for Microsoft Windows – Provides image-based backup and recovery for Windows systems. The interface may not be as user-friendly as other options.

Backblaze – Backs up unlimited data for a low yearly fee and includes file versioning. But initial backups can be slow on large datasets.

Macrium Reflect – Full disk imaging and file backups. The free version covers most key features but advanced options require upgrading to paid versions.

Overall, top backup software provides comprehensive protection for files and systems, with capabilities like incremental backups, encryption, and scheduling. The choice comes down to factors like price, features needed, and ease of use.

Cloud Backups

Backing up data to the cloud has become a popular way to protect important files and documents. Cloud backup services provide offsite storage by saving copies of your data to remote servers accessed over the internet. This protects against local failures like hard drive crashes, ransomware, theft, or natural disasters.

Some of the major cloud backup services include:

  • Backblaze – Offers unlimited storage for $6/month. Backblaze backs up automatically and continuously.
  • Carbonite – Carbonite offers plans for home and business, with unlimited storage options. It provides mobile apps and options for server backup.
  • IDrive – IDrive Express backs up locally first then sends data to IDrive cloud servers. It offers 5TB of storage for around $50/year.
  • Google Drive – Google Drive isn’t a dedicated backup service but offers significant storage as part of G Suite plans. It works seamlessly with Google services.

Key features of cloud backup services include automated scheduled backups, unlimited storage options, and the ability to access files from anywhere. Backing up to the cloud provides an extra layer of protection for irreplaceable data.

Backup Frequency

Determining the ideal backup frequency involves balancing business needs with practical limitations like storage capacity and bandwidth. Most experts recommend a minimum backup frequency of once per week, with daily or even hourly backups for mission critical data.

According to Total IT, daily backups are recommended for important business data that changes often. Weekly full backups are sufficient for data that doesn’t change frequently. Backups can be automated and run as scheduled tasks, minimizing the administrative burden.

More frequent backups provide greater protection but require more storage capacity. Organizations must weigh the costs of additional storage against the potential impact of data loss. Key factors include how critical the data is, the rate of change, and recovery time objectives.

While daily or hourly backups are ideal for rapidly changing important data, less frequent weekly or monthly backups may be sufficient for things like documents and media files. The right balance depends on each organization’s specific needs and acceptable risk tolerance.

Retention Policy

A backup retention policy specifies how long to keep backup data before it can be deleted or overwritten. Determining an appropriate retention period involves balancing storage costs against the need for restore points. There are also legal requirements that may dictate minimum retention periods.

According to industry best practices, a tiered retention scheme is recommended such as:

  • Keep daily backups for 1-2 weeks
  • Keep weekly backups for 4-8 weeks
  • Keep monthly backups for 6-12 months
  • Keep yearly backups for 2-7 years

Backup retention policies help prevent storage from filling up and also make restores easier by limiting the number of recovery points. However, regulated industries like healthcare and finance have legal minimums they must adhere to. For example, HIPAA requires healthcare data be kept for 6 years in most cases (Source).


In summary, implementing a solid backup strategy is critical for protecting your important data. The 3-2-1 rule provides a simple framework – have at least three copies of your data, stored on two different media types, and at least one copy offsite. Combining onsite backups like external hard drives with offsite cloud backups provides both accessibility and protection against localized disasters.

Choosing the right backup software and backup frequency to automate the process ensures backups are happening regularly. Retention policies prevent outdated backups from accumulating and wasting storage space. Overall, a good backup plan takes some work to implement initially, but saves huge headaches down the road if data loss or disasters occur. The peace of mind of knowing your data is secure and recoverable is well worth the effort.