Consolidation not working like it should

I recently posted about an error in my backups that I found out was due to consolidation. I started reading some posts on here about how it's supposed to work. I then did an experiment.
I created a backup location on my hard drive and the only limit I put was for size at 50 MB.
I then created a scheduled task to backup a folder that has some PDFs in it. I set the task to do incremental backups to my backup location and to create a new full backup after 2 incremental backups. Each time I would manually run the task, I would create a copy of a PDF file in that PDF folder. So my first backup had a copy of this file in it. Then for the next run, I copied that file again, so I got Copy (2) of XXXXX. I then ran the backup again. I kept doing this until the backup location was full. By this time I was at Copy (7). During this backup, I saw it doing consolidation with the long filenames and then it finished. I was of course left with less backups. I then browsed each of the backups that were left, and to my surprise, none of the backups had Copy (7). With the 3 left that I could access, I had the 3rd backup, the 5th, and the 6th.
This didn't make sense, so I tried it again multiple times making a copy of a different file so it would be a different amount of backups before it would go above the quota. Every time I did it, none of the backups left would have the last copy I was supposed to have, meaning the latest backup wasn't there.
If this is the case, the backup locations could cause me to lose my latest backup, which kills the usefulness of the backup location quotas. Has anybody ever tested this consolidation process with success? I even tried reinstalling the program and it does the same thing.
I am using TI Home 11 build 8,053.

Update: I tried doing the same thing at home with the same results. When setting a space limitation on the backup location, the backup that leads to the consolidation is not there after it completes.

 

If you have only one backup set, wouldn't the last backup be incorporated into the consolidated file? That doesn't excuse the any files missing form the consolidated backup but I would expect the last backup, the one that prompted the consolidation to be gone after the consolidation is done.

 

Yeah...I wasn't as concerned with how many backup files were left, but I checked all of the backups including all of the slices in each backup, and none of them left had the latest PDF file, meaning the last backup did not exist or get incorporated into anything.

 

That goes into the Category of critical failure of fundamental purpose. I wonder if this is a generally repeatable condition (happens to everyone that tires it) or just on some set-ups.

 

I just tried this again, but this time I removed the size quota and added a 5 backup limit. I tried it multiple times and my last backup was always there, so the # of backups quota seems to work. I will investigate the size with differential backups to see if that makes a difference.

Update: I tried it with differential instead of incremental and I got the same results.

 

I've just run this test with the same settings as in Post #1. I think this falls into one of those difficult categories because of the unique situation.

The 50MB limit forces the consolidation to take place when the quota is reached. What happens is that no "real" consolidation can take place. In other words, the amount of space used is still the same as before. This is because (in this scenario) a new file is being added every time. There are no "updated" existing files in the backup to be "consolidated" into a previous backup. This means that all TI can do is merge the first incremental into the full. It does this on both sets (I had two before the quota was reached). There were no space savings.

The only questions that remains is why TI didn't finish the backup. Once the consolidation takes place, there is room for the second incremental on the last backup set. However, TI does not do a new backup.

My guess is that since TI already checked and there wasn't enough room, it did the consolidation and then stopped. It does not check afterwards to see if it can run the backup without running over the quota. The way TI looks at it from the start is that it was time to create a new full backup image. There is not room for the full image, not before the consolidation and not afterwards. Then, TI falls back on the normal "abort without deleting anything so the user at least has their old backup" strategy.

If the task is run again, the second incremental is created on the last backup set and it includes the previously not backed up file.

 

According to the flowchart here:
https://www.wilderssecurity.com/showpost.php?p=1092441&postcount=67
I would think that it would keep trying to consolidate until everything is under the quota, and if it can't consolidate any more and it's still above the quota, then it will delete the oldest backup. That means I should still have my latest backup somewhere.
I see what you're saying, but like you said, there should be no reason why the last backup that caused the consolidation is discarded. The only thing in that flowchart about deleting is about deleting an older archive...not the current one that just processed.

 

I ran it again and looked at the folder while TI was processing the backup. It does create the new backup image. It does put it over the quota.

From there, it consolidates 1 incremental in the oldest backup into its full.
Then it consolidates 1 incremental in the next oldest backup into its full.
Then, because it's still over the quota, it deletes the NEW backup image.

It should be deleting the OLD backup images as necessary to make room. The log doesn't list the filename for the last deletion, but it has to be the new backup because that's when it vanishes from the folder.

 

Thanks for doing that test and verifying where the new backup disappears.
I did a support request last night. If they respond I will give them the link of this thread as more evidence that there is a problem.

 

Hello nhl2k and MudCrab,

Thank you for choosing Acronis Disk Backup Software.

I have just run a similar test and can confirm that the last backup indeed does get deleted with specified setup. I will forward this to our Development team.

nhl2k, could you please let us know your Acronis request number (e.g. [Acronis #123456]) which was sent to you in autoreply to your letter? If you have not received an autoreply then please send us a Private Message containing your e-mail address.

Thank you.
--
Marat Setdikov

 

Thank you very much for responding Marat, and especially for running the test to verify my results. Here's the subject from the first email response I just received this morning from Vladimir:
[Acronis #1299728] Consolidation not working like it should