Backup Basics



There are many things that can cause data loss, including human error, hardware failures, and natural disasters. Even if you are careful with your computer, you can't always prevent these kinds of events from occurring. No one is immune, so be prepared and have a backup plan in place.

Why Back Up?

1. Human Error -- The most common reason for data loss.

Data loss in individual files or folders is a threat. This can happen if you accidentally delete files or folders, reformat the system drive by mistake, or make mistakes while using the computer. To protect against this, use a "versioned" backup of your working files on a local external drive with Time Machine, Arq, or Chronosync. These apps let you restore earlier versions of files and folders that might have gotten damaged or deleted.

2. Hardware and Software Failures -- These can and do happen.

If you lose a lot of data, applications and settings, or if your computer stops working, it could be due to a system drive failure, corruption in the operating system or application files, or other local problems. To prevent this, make regular backups of all your data using Arq, Chronosync, or Carbon Copy Cloner. Save these backups on external drives that are separate from the versioned backups. All drives can fail, so it's important not to rely on just one.

3. Catastrophic Events

If you lose your computer, data, or local backup drives, it could be due to a natural disaster, fire, theft, ransomware attack, or other major event. To protect against this, regularly update the off-site backup of all important data. Use apps such as Backblaze or Arq-cloud that run in the background to give peace of mind. Consider this as homeowner insurance.

Keep in mind that no single backup solution is perfect, and it is important to regularly test backups to ensure that they are working correctly. It is also a good idea to have multiple copies of your data in different locations in case one of your backups fails.


It is generally safe to use standard spinning drives for backup. Solid state drives (SSDs) are faster and may be more reliable in the long term; however, they are more expensive. When making versioned backups, it is a good idea to use a drive that is at least twice the size of an internal computer drive. Some recommendations for reliable drives are as follows:

  • Seagate
  • LaCie
  • OWC Mercury Elite Pro
  • Western Digital My Book
  • Toshiba Canvio Basics

Note: Always use Disk Utility to erase and reformat external drives before use. Also, don't use the backup software that comes on many of these drives.


Time Machine is a convenient solution for automatic versioned backups on Macs, but it does have some limitations. It does not allow you to change the 1-hour backup interval, alter the backup selections, or change the retention rules. If you need more control over your backups, you may want to consider using a different backup app. Here are some options:

  • Arq 7: This app allows you to create versioned backups of your Mac to a variety of different destinations, including local, network, and cloud storage. It has a range of options for scheduling backups, selecting the files and folders to include, and setting up custom retention rules.
  • ChronoSync: This app allows you to synchronize files and folders between different locations, including local, network, and cloud storage. It has a wide range of options for scheduling backups, selecting the files and folders to include, and setting up custom retention rules.
  • Carbon Copy Cloner: This app allows you to create bootable backups of your Mac's system, and it gives you more control over the backup process. You can choose the files and folders to include in the backup, schedule backups to run at specific times, and set up custom retention rules.

By Phil Davis. Updated: 2023-02-25