A Basic Explanation of Backup types and Methods as Apply to Linux and Windows Dell Computers

Table of Contents:

1. What does Backing Up involve and why is it needed?
2. Types of Backup
3. Backup Methods
4. File Systems
5. Recovery

What does Backing up involve and why is it needed?

Backup and recovery are essential on any device. Not having a verified backup and recovery procedure puts your data at risk of loss.

People often learn this only after their data is lost for good. Any Attempts at recovering lost data loss can take up h a lot of your time and a lot of money. Ensure that you have a plan in place that protects your data in order to ensure that this never happens to you.

There are several questions to ask yourself before you look at putting a plan in place:

• Why are you protecting yourself against disaster?
• Does it matter if you lose data?
• What losses would you suffer?
• What are you going to backup?
• The whole hard drive or some of the data?
• When is the best time to backup your computer?
• How often would you perform a backup?
• When would you use full backups and incremental backups?
• Where would the backups be stored?
  • Stored On-site?
  • Stored Off-Site?
  • Stored on the Cloud?
• What Media type?
  • Attached storage?
  • USB stick?
  • USB hard drive?
  • Tape drive?
  • Backup server?

Types of Backup

There are many different ways and different software out there to provide backup and recovery. Making the best choice for you must consider several things:

Recovery time objective (RTO):

How fast would you need the data back up? Can you keep working if the data is not recovered for a day, a week, and so forth?

Recovery point objective (RPO):

How much data are you prepared to lose? Can you lose two hours, two days or two weeks of data?

For example: If you can withstand losing one week of data, then a weekly backup would be sufficient. However, if you can only withstand losing one day then you would be required to employ a nightly backup - or a variation.

This article covers three basic types of backup:

Full:

A full backup backs up everything in the location you select.

Incremental:

An incremental backup backs up everything that has changed since the last backup.

Differential:

A differential backup is the same as an incremental if your running Linux or macOS. In Windows, it is a backup that does not clear the archive bit.

Backup Methods

You can choose from these three methods. (Depending on the money that you have to spend and the specific RTO and RPO you have selected.) :

Manual:

Manual backup can be initiated on a schedule by you and is the most common method for home users to backup your files. This method is also the least reliable, but is the cheapest.

Local automated:

Automated backups are ones that target media physically attached to the computer being backed up. Advanced home users and small businesses often use this method.

Remote automated:

Automated backups are ones that target media over a network. Businesses that have money they can dedicate to the process of backup use this type of backup. As the organization becomes more mature, they may even stage the backup on multiple mediums and increase the distance between backup and production computers.

File Systems

Ubuntu file systems record three different times for each file:

mtime:

Modification time is when the value is changed when the contents of the file is changed.

atime:

Access time is when the value is changed when the file is accessed. The atime can change when a backup utility or script reads the file in addition to when a user reads the file.

ctime:

Change time is when the value is updated whenever the attributes of the file change. This can be ownership or permissions.

Windows file systems record only two for each file. It is either set or clear.

Archive:

When set, it indicates that the file has changed since the last backup operation. Windows file system sets this attribute on any file that has changed. Backup software then has the duty of clearing it upon a successful backup.

Recovery

It is crucial that your backups be tested by restoring from them.

Here are some tests that you should do to ensure you can recover from a loss:

1. Restore many single files.

2. Restore an older version of a file.

3. Restore an entire folder.

4. Restore an entire drive and compare the checksum.

If you do not test, you may find out that nothing was being backed up when you must restore the files in reality.

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