So I have a large RAID external drive that backs up to a second RAID external drive of the same size. By large amounts I'm talking like 10 TB. As you can imagine, creating such a large backup from scratch would take immense amounts of time, so incremental backups are a necessity.

I have been using Comodo backup. One problem I'm having is there is only enough space on the backup drive for a single backup.

I'm doing incremental backups. But if an incremental backup were to have an error, this would spoil the entire backup correct? I couldn't revert to an earlier backup since there is only space for 1 backup.

I have looked into split backups. If there is a backup error does this mean only the piece where the error occurred would have to be backed up from scratch?

Basically if there is an error I don't want the entire backup to be spoiled.

How to best handle this concern (e.g. tools to use, best practices, etc)? Thanks!

Edit: The tool must properly backup hardlinks

  • Must you backup regularly (e.g nightly)? Or, would you be willing to mirror? One huge copy and then every time a single file gets changed that change is immediately reflected on the backup drive? I am doing that with 6TB and highly recommend bvckup2.com
    – Mawg
    Commented Jan 29, 2015 at 10:43
  • Mirror sounds like a good idea. Then if there is an error backing up a changed file, only the newly backed up file is affected? I guess then my only problem would be as I change a file on one a file gets changed on the other which could slow real time performance (since if you were to create a large file, E.G. downloading a video, that large video gets downloaded to the backup as well). So maybe schedule the mirroring to take place at night or something? Would that be possible?
    – Wes
    Commented Jan 29, 2015 at 16:37
  • Nope: if it is scheduled, then it is, by nature, a backup. Mirroring happens at once. However, I tend to download a lot of (legal) videos and have not noticed any slowing. YMMV; so suck it & see
    – Mawg
    Commented Jan 30, 2015 at 10:44
  • bvckup2.com looks like a cool tool but I need a tool that will properly backup hardlinks and it looks like this tool does not.
    – Wes
    Commented Jan 31, 2015 at 4:48
  • Well, the author was looking at adding support 2.5 years ago bvckup2.com/news/02-11-2012 Perhaps you can email him & confirm? After all, you have no othehr suggestion so far
    – Mawg
    Commented Jan 31, 2015 at 8:29

2 Answers 2


As per my answer here ...

You don't mention that it must be free. I would highly recommend paying US $19.99 for a personal version of Bvckup 2. I did, and I have never regretted it.

I did a lot of research before choosing it, and what convinced me was partly that it supports VSS, so that it can synch files which are in use, and, especially, the speed, it wins every test because it uses delta copying:

Reduce the amount of data being moved around by copying modified parts of files only. This speeds things up, in many cases dramatically.

enter image description here.

There is a 5 start review of it at PC World.

If you don't want to spend, or just want to try it out, the last beta, which is quite recent, is available here.

If you still don't like Bvckup2, then I can highly recommend FreeFileSynch, which I previously used. See my long answers to this SR question, and this one and this one too.

To save you the trouble of clicking those links, here is the feature list:

Key Features

Detect moved and renamed files and folders
Copy locked files (Volume Shadow Copy Service)
Detect conflicts and propagate deletions
Binary file comparison
Configure handling of Symbolic Links
Automate sync as a batch job
Process multiple folder pairs
Comprehensive and detailed error reporting
Copy NTFS extended attributes (compressed, encrypted, sparse)
Copy NTFS security permissions
Support long file paths with more than 260 characters
Fail-safe file copy
Cross-platform: Windows, Linux, Mac OS X
Expand environment variables like %USERPROFILE%
Access variable drive letters by volume name (USB sticks)
Native 64-bit support
Keep versions of deleted/updated files
Prevent disc space bottlenecks via optimal sync sequence
Full Unicode support
Highly optimized runtime performance
Include/exclude files via filter
FreeFileSync portable and local installation available
Handle daylight saving time changes on FAT/FAT32
Use macros %time%, %date%, et al. for recurring backups
Case-sensitive synchronization
Built-in locking: serialize multiple jobs running against the same network share 

Supported Operating Systems

Microsoft Windows Microsoft Windows FreeFileSync runs natively on all 32 and 64-bit Windows versions:

Windows 10
Windows 8.1
Windows 8
Windows 7
Windows Vista
Windows XP
Windows 2000


I use the Smart Mirror option, running it every 30 minutes with Windows Task Scheduler and it works great, perfectly mirroring the primary.

  • 1
    Welcome to Software Recommendations. We want answers that explain how the recommended product matches the requirements and fits the purpose of the question. Could you expand it to demonstrate how this product fits? See this meta post for tips on writing an answer. Commented Feb 8, 2015 at 19:12
  • The website talks about a tool that can be used for backups, which is what the topic is about. I don't know what else to say really...
    – Wes
    Commented Feb 11, 2015 at 17:18
  • I also wrote the question so you can be sure my answer answers my question.
    – Wes
    Commented Feb 11, 2015 at 17:24

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