Acronis incremental does a FULL backup after a restore completes - why can't it just continue on with the incremental changes?

I may not be correct in this but I believe that when you restore an incremental backup as you suggest the incremental V2 and V3 in your example are merged into the initial full.  When you start the incremental backup task again the Full backup is rolled forward if you will to include V4 thus resulting in a full sized backup.

I suspect that this is related to the fact that a restore requires every sector of the disk to be re-written. Not 100% sure, but also assume that the data doesn't necessarily end up in precisely the same physical sectors as before. The block level change analysis ATI performs for an incremental backup would therefore likely see most or all sectors as having changed. 

It might be different if you used the "forensic" option of backup up all sectors including empty ones - although still not certain that they'd be written back precisely as read. 

My personal preference after any restore is to stop all existing tasks related to the restore and start new task(s).  I will keep the old tib files until I was positive the data on the drive was as I expected and the new tasks were performing as expected.

Thanks for all the replies. It sounds like there may not be a solution to this...

Based on what I know about the process, it seems like this *should* work - but maybe there's something about restoring an OS that I do not know.

It really only impacts my test environment. I like to make changes, backout of something that doesn't work the way I anticipated (using Acronis restore) back to the safe point, and then move forward again with a new acronis incremental backup. It's the 'move forward' part that takes longer as the 'incremental' backup is now the size of a full and thus takes longer to backup.

All good, was just checking! : )

-Bob

"It might be different if you used the "forensic" option of backup up all sectors including empty ones - although still not certain that they'd be written back precisely as read."

I thought of this too and I believe I attempted to try it at one point but the problem is that the sector-by-sector backup produces an EXTREMELY large file so it kinda negates doing this anyway.

Hi there,

my problem which i currently have is similar, but a little bit different:

I am still using ATI 2013 for specific reasons.

I do have a file-backup of a disk which contains data files only, no OS. That backup has 1 Full and 7 small incrementals.

Now i did reconfigure my HDD with moving and sizing the paritions in a different way. After doing that i did restore the file-backup without any issue.

Today i started a next incremental backup, and a full backup is created. Why is the software doing that and how can i prevent that? Is the archive used to distinguish between old and newer or changed files, and was the archive flag maybe set when restoring the data?

It may have something to do with ATI working on a block by block basis. The procedures you describe could result in the physical location of files changing, and they are in different data blocks. In those situations an incremental backup would be the approximate size of a full backup. Defragmenting a HDD can have similar outcome. Fortunately SSD do not require defragmentation - and the Trim process does not impact blocks with “current” data.

Ian

Oh oh... i have some new information about the issue:

I did test, before restoring, that one can create another incremental piece of the drive after the restore. I have found my older documentation about that.

So i gave it a try, did restore on the same drive letter, then i added some files, and the next incremental backup did work as expected, only a small file was generated, very fast.

Now i started asking myself what i did in between, that the current situation is different, and i remember that i had some permission problems after restoring the files. And yes, i did have the same issues with this new test as well. So i did the same steps as last time... basically i did change the owner of the data by right-click on the drive letter in windows explorer, then Security, then the "additional settings" button on the bottom (in german it says "erweitert"), and then exchange the owner on the top of the page for this place and everything below.

After that, trying to create a incremental backup again, did fail, it did start to generate a full backup.

How come ? Why is this happening?

First of all.... why did i have issues with the permissions after doing a file restore.... and why do i now get trouble with creating additional incremental backups after i have fixed my permission issues ?

Question:

There is this option for recovery with one can select, if the files will be restored with their original security settings... which is active by default.

I am starting to think that i should have deactivated that switch.... so that no security issues are transferred from the old computer to the new one, and the restore would have simply restored the files without generating any troubles in securities ???

If you are restoring files to a different computer then you should always opt to not recover the files with their original permissions.

It doesn't matter that the new computer has a user with the exact same user name as the owner had on the old computer, the two users are not and will never be regarded by Windows as being the same, so the permissions will be wrong!

I have hit this same issue when needing to repair a bad user profile on the same computer and had to create a new user profile that I gave the same name (after renaming the bad one).

Then.... this is the root cause of a lot of troubles....

Too bad that this option is set by default...

Thanks for your help !

so.. my last trial was to restore all files without recovering their original permissions. In the hope, that the next incremental then might be a small piece.

No... that does also not work, it creates a new full backup instead.

Can't i disable the check for the permissions which ATI is doing here?

That means that nobody would be able to continue an incremental backup-chain, once the backup is needed ! Once you have to rebuild the machine and install a new OS on it, then all files have (from the view of ATI) a new persmission setting and an incremental backup is not possible any more...

If we step back a little in this issue.

Are you recovering files to the same or a different computer here?

Where was the backup created, was it on the original computer or the different one?

A backup can only be continued on the same computer where it was created - if you take that backup to a different computer then the partition unique id's for the task will be difference and will cause a new full backup.

It is a new computer and new hardware.

Same harddrive but partitions were deleted and newly created, in order to change also size of the partitions.

New installation from scratch of windows 10, no copy of an image.

All that was done in January this year, and i did restore my file-backup successfully on 2 partitions, but with including their original permissions.

Because i am somewhat desperately trying to get a chain of increments i did a lot of tests and my findings are different:

• If i create 4 partitions on one harddrive, and then i make a filecopy of the first two partitions, then i rename the driveletters so that the last two partitions get the letters of the first two... then i restore, add one file, and try incremental backup... works perfect. So i have my doubts about the partition unique id stuff.
• If i make a file copy of one partition, delete that partition, create it again, restore the data, and change on file... a incremental backup is done. If i now change permission in that drive in that i change owner of all items on that drive, add another file and try one icnremental... it makes a full backup.

I have tested the first one beginning this year with success, and now have tested it again. I was wondering why my plan to create another increment did fail that miserably, and i did remember that i had issues with permissions on the drives after restore, so i did check if this is the one change with forces ATI to think it needs backup all files in the incremental, and it seems as if it is that way.

Thanks for the clarification about what you have been doing and the outcomes seen.  It looks like you have reached a conclusion about what changes will allow a new incremental file and which will cause a new full backup.

Well... i am surprised about the fact that with switching to a new computer the backup chain cannot be continued.

Obviously, even when entering the same username, profile and passwords, it still looks for ATI that this is a different user account, and with that the permissions on the files are for somebody different.

It's a little bit of "exactly at that point when you need the backup, the backupsystem starts to struggle". Sure, i was able to restore without a problem, but i cannot continue my backups as i was used to.

I did not know at all that ATI checks this data as well... but yes, i guess that many people want to have the permissions with the files stored, and so ATI has to backup everything after the owner of the files has changed.

So this was my last reason to stick with ATI 2013.... with that i did buy today the upgrade to 2019 and i still have to decide if i will start a new backup-set, or if i will start the work to restore and backup every incremental version of my files in order to recreate the incremental chain on new computer, with new user-profil, and new ATI.

Lets see which surprises i will see there ;-)

Thanks for your support !

I found this

https://www.acronis.com/de-de/support/documentation/ATI2019/index.html#…

which describes the options i have while creating a file backup in ATI 2019... in the extended area. It says that i can choose if i want to backup the files including their security permissions or without the security permissions. It also says that i can do that as well when i restore the files... the result would be exactly the same.

Here are my 2 questions:

• i did not find such an option in ATI 2013... did i simply not find it or is there no option like that?
• i would assume that the result would not be exactly the same, as i would assume that if i do not backup the file including their permissions, then the files would not be rated as change in the next incremental session, if the permissions on the computer had changed?

See the ATI 2013 User Guide: File-level security settings for backup which shows the same options were present.

Changes are not determined by permissions or changes at a file level, but changes detected at a sector level.

Wow... never found that switch, will check if i can find that.

Before redoing my next backup i will also run a test to check if my assumptions in the post above are correct or not...

So, here we go...

Yes, the option to enable the backup of files without their security information is available, in both versions ATI2013 & ATI2019.

And yes, if i deselect that checkbox and do backups in an incremental chain, then, after restoring, and after changing the ownership and security settings of the files, i still can create a small incremental backup after that. So that is what i wanted to achieve.

So there is a difference between disabling the security settings at backup time or disabling the security settings at restore time: If you choose that already at backup, your incremental chain of backups can be continued after restoring the data to a new machine.