Suggestion for my backup plan?

Lady Fitzgerald said:

cyberSAR said:

Not necessarily. In incremental if day 2 is corrupted you lose those files (unless they were also backed up on day 3) but day 3 would be fine.

Look at it this way. If you do a full backup and 5 days of incrementals to restore you would restore the full backup then day 1, then day 2 then day 3 then day 4 and finally day 5.

In differentials you would restore the full backup then day 5. No need for days 1-4 as they are contained in day 5s backup.

hope that helps.

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You are confusing incrementals with differentials. An incremental includes only data since the previous image, be it a full image or an incremental image. With incrementals, all copies have to be present and uncorrupted for full recovery. If day 2 is corrupt, you will only be able to restore with the initial full image and the first incremental. You will not be able to use day 2 and any day after that.

Differentials, on the other hand, include all data from the last full image. When restoring, only the initial full image and the last differential is used. If day 2 is corrupted, it doesn't matter since only the last one will be used. Differentials are safer than incrementals but take up more space since each one is larger than the previous on. However, full images are much safer than either incrementals or differentials.

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I'm not confusing incrementals and differentials in a file based backup. I use Cobian for my data backups and if day 2 was corrupted due to bad sectors or corruption during file copy process, encryption, compression etc, those files would not be usable but everything thereafter would still be usable.

In something like Acronis or macrium you would need all copies to work for incrementals. That's one of the reasons why I don't use imaging for my data backups.

pcwin, you may want to read through Cobian - Backup theory for some ideas and theory.

cyberSAR said:

Lady Fitzgerald said:

cyberSAR said:

Not necessarily. In incremental if day 2 is corrupted you lose those files (unless they were also backed up on day 3) but day 3 would be fine.

Look at it this way. If you do a full backup and 5 days of incrementals to restore you would restore the full backup then day 1, then day 2 then day 3 then day 4 and finally day 5.

In differentials you would restore the full backup then day 5. No need for days 1-4 as they are contained in day 5s backup.

hope that helps.

Click to expand...

You are confusing incrementals with differentials. An incremental includes only data since the previous image, be it a full image or an incremental image. With incrementals, all copies have to be present and uncorrupted for full recovery. If day 2 is corrupt, you will only be able to restore with the initial full image and the first incremental. You will not be able to use day 2 and any day after that.

Differentials, on the other hand, include all data from the last full image. When restoring, only the initial full image and the last differential is used. If day 2 is corrupted, it doesn't matter since only the last one will be used. Differentials are safer than incrementals but take up more space since each one is larger than the previous on. However, full images are much safer than either incrementals or differentials.

Click to expand...

I'm not confusing incrementals and differentials in a file based backup. I use Cobian for my data backups and if day 2 was corrupted due to bad sectors or corruption during file copy process, encryption, compression etc, those files would not be usable but everything thereafter would still be usable.

In something like Acronis or macrium you would need all copies to work for incrementals. That's one of the reasons why I don't use imaging for my data backups.

Click to expand...

Yes, you are confusing them. This website has the best description I could find about Cobian Backup (the Cobian Website was useless). From the website is this:

FULL The Full option will make Cobian backup every single file you specified even if it has not changed since the last backup. By default this type of backup will create backup folders containing the time stamp of when the backup ran. Regardless of the Backup Type you select, the first time a task is run it will perform a Full install.

INCREMENTAL This is the feature you will most likely be using after creating your first backup instance. It checks if the source has changed from the last backup and only will backup those files that are new or have changed since the last backup. This saves a lot of time and space on your PC or the medium you will store your backup upon.

DIFFERENTIAL This setting works in the same way as incremental but instead compares the files from the last Full backup. If the current files are different compared to the last Full backup it will back up that file.DUMMYThis setting does not actually back up any files but can be used to schedule the execution of programs, close services, reboot the computer, etc.


You will find that the descriptions of Incremental and Differential backups are identical to the one I gave and the one given by Macrium Reflect.

Btw, we have been discussing imaging when referring to incrementals and differentials. From what I could see, Cobian works more like a folder/file syncing program, only more cumbersome. I do agree imaging should not be used for backing up data. However, it pretty much is essential for backing up system files.

Trust me Lady Fitzgerald I am not confusing incremental and differential. I use one or both on numerous machines daily.

I thought the OP was going to use macrium for images and free filesync for data (may have missed a few posts). I thought free file sync did a file based backup similar to Cobian but I may be wrong about that.

With Cobian or Robocopy or whatever file based, non-proprietary format I choose I can certainly skip a day of incrementals and still have usable files in the later set. I will NOT have a complete restore if I skip a day (and the files from that day haven't been backed up at a later time).

Apologies to pcwin if I misunderstood and you were referring to incrementals in macrium. Whatever you choose, test it, break it and test it again. Backups are useless if you can't restore them.

Whilst you were pissing about with incremental and differential...pcwin probably missed this?

Golden said:

Whilst you were pissing about with incremental and differential...pcwin probably missed this?

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Thanks, I did see it, but I did not try yet.

For the Sychronisation method, do you choose Echo or Synchronize or Contribute?

cyberSAR said:

Trust me Lady Fitzgerald I am not confusing incremental and differential. I use one or both on numerous machines daily.

I thought the OP was going to use macrium for images and free filesync for data (may have missed a few posts). I thought free file sync did a file based backup similar to Cobian but I may be wrong about that.

With Cobian or Robocopy or whatever file based, non-proprietary format I choose I can certainly skip a day of incrementals and still have usable files in the later set. I will NOT have a complete restore if I skip a day (and the files from that day haven't been backed up at a later time).

Apologies to pcwin if I misunderstood and you were referring to incrementals in macrium. Whatever you choose, test it, break it and test it again. Backups are useless if you can't restore them.

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Good grief! Did you not even read what I quoted that defined Cobian's use of incremental and differential?

pcwin said:

Golden said:

Whilst you were pissing about with incremental and differential...pcwin probably missed this?

Click to expand...

Thanks, I did see it, but I did not try yet.

For the Sychronisation method, do you choose Echo or Synchronize or Contribute?

Click to expand...

It depends on what you are trying to achieve. For a simple backup, use Echo.