Bare Metal Vs File-level Backup
The importance of data in today's corporate world is akin to a heart in a human body. A company's reputation can be
severely damaged if data is lost. Not only must data be backed up on a regular basis, it must be easily accessible and secure.
Your backup strategy is like an insurance policy - it should include protection against hardware failures, viruses,
data corruptions as well as a natural disaster.
When it comes to backup, you have a choice of either backing up the entire disk or the
individual files. Each approach has pros and cons. This article makes compares these approaches in detail.
Bare Metal Backup
As the name suggests, a Bare Metal backup takes an image of the disk and backs it up to a backup repository. The backed up image can either be
on a DAT tape, an external USB drive, on a private-cloud backup repository within your company or even on a public cloud. During restore,
the entire disk can be restored in its pre-crash state. Many Bare Metal backup solutions store the backed up file as virtual hard drives.
This will allow administrators to mount a VHD file into a live operating system and extracting individual files.
Unlike Bare Metal, a file-level backup system will only backup individual files rather than the entire system image. A user can decide a subset of files that are important and the software will then back up those files to the target media.
We will be comparing these approaches against the following criteria
- Protection against total hardware failure
- Protection against partial hardware failure
- Protection against viruses and malware
- Data verification and testing
- Accessibility of backed up data
- Storage requirements
A score is assigned from 1 to 10 for both approaches and a summary table is displayed towards the end of this article.
Protection against total hardware failure
The ability to restore an entire disk to its previous state makes Bare Metal backups undoubtedly better than File-Level.
Using previously backed up disk images allow administrators to rebuild a crashed computer quickly.
Recovery time is longer when restoring a File-level backup. A typical restore will involve reinstalling the entire operating system from its original disk, reinstalling the software applications and then finally restoring individual data files from the back up.
Partial hardware failure
Bad sectors on a disk constitute a partial hardware failure. Many Bare Metal backup systems will fail during backup if they
encounter a physically damaged disk, allowing users to fix the problem before it too late. Although some backup vendors allow
an option to ignore bad sectors and continue with a backup, you may run into problems when it's time to restore. Either way,
the entire backup is affected if there are bad sectors on the disk.
A File-Level backup is more forgiving when it comes to partial disk failures. In this case files residing on a bad
sector will error out during backup but the remaining files should get backed up.
Protection against viruses and malware
Often viruses stay dormant on a machine for quite some time and become active on a certain day. Some malware software continue running in a stealth mode without any visual indication.
Viruses can be assigned into three categories:
- Stand-alone executables
- Plugins that run inside a browser
- Scriptable documents - such as embedded scripts in an MS Word document
A Bare-Metal backup does not provide any protection against such malicious programs. If a computer is infected with a virus prior to backup,
it will be present in the restored version of the machine.
A File-Level backup is much better when dealing with viruses. Although it does not guarantee a malicious program will not get restored, it will certainly eliminate the first two types of viruses mentioned above.
Data verification and testing
A backup is only useful if it can be restored. Therefore, it is important to regularly test the backed up data to verify it can be restored before it is too late. This testing should not be a one-time event. Instead, tests must be performed on a regular basis to ensure data integrity.
Testing a Bare Metal backup is often much more time consuming then testing a File-Level backup. Even though many Bare Metal
backups store data as virtual disks, the image containing the operating system and boot sector can only be tested thoroughly
by rebuilding the entire computer. Since this takes more resources, many administrators do not test backed up data until it is too late.
Testing a File-Level backup is much easier. Since files are available in their raw format, testing is usually much simpler. Some software even provide a built-in comparison report showing differences between backed up data and the actual machine.
Accessibility of stored data
Accessing a Bare Metal backup is usually not as easy as a File-Level backup. Some File-Level backup software, such as Syncrify
, allow access to backed up file through a web browser. This means you can easily access your files from anywhere, anytime on any device. Imagine the convenience of accessing an important document via your iPhone or Android device.
Additionally, backed up files can also be used to synchronize folders residing on different computers. This can be done by pushing files from one machine and pulling on a different one.
With the growth of disk sizes on desktops, laptops and servers, backing up large data becomes challenging. When using Bare-Metal backups the storage needed to hold this backup must also be as big as the original data, which could add up to a very large number.
Since File-Level backups typically only backup important data files, the storage requirements are drastically reduced.
Based on the explanation above, the following table uses a scoring mechanism to rate both Bare Metal and File-Based backup solutions.
Each score is a number between 1 and 10.
|Criteria||Bare Metal||File Based|
|Total hardware failture||10||5|
|Partial hardware failture||6||10|
Which option is good for me?
Every scenario is different, therefore, you have to make a decision by evaluating your needs.
One approach is to consider using Bare Metal backup on servers that run background processes and are
less vulnerable to virus infection. Consider using File-Level backups on laptops and desktop machines
that have user documents, music files, pictures and other such artifacts.
supports both Bare Metal
backup. Use this article to decide which approach is better in your scenario. Often users decide to use both method to
ensure the integrity and accessibility of their precious data.