Why older backups contain newer files

re: 2) - may be there is no difference at all - if it shows the timeline up to the last backup (5 Jan) even if the one from the middle is selected initially, it considers the whole chain.

Hi Dataman

From my understanding you have done the following:
- Restoring a file called “newfilecreated4jan1pm.txt”
- Chose your backup archive to restore from “MyBackup2.tib”
- Then chose to restore the file from “5 Jan”

I think what ABR11 has done is correct; it should have restored the file as it was on the 5th Jan as that is the date you told it to restore from?

All incremental backups are linked to a full (or a previous incremental/differential backup), when you select to restore from that file you can select any date in the possible range to restore from, in this case you have selected to restore from “MyBackup2.tib” which basically just tells Acronis what chain of backups you want to restore from, the next step is actually the date/time/backup you want to restore from, in your case you selected to restore the file from 5Th Jan.

A quick test you can do is as follows... Open up your “newfilecreated4jan1pm.txt” file and add some extra details to it (Eg, Extra text added for further testing)... Close and save the backup..

Perform another incremental backup, then perform a restore but in the last step restore the file again from 5 Jan and you should see that text is missing, do another restore but this time from the latest date and you should see your text has come back... the archive you specify initially is not all that important as ABR11 will be able to restore from any other backup that it’s linked to as well.

Hope that makes sense and helps out...

I have done further testing and I do notice that it does not matter which backup .tib date is selected in the "backup archive selection". As long "backup date selection" date is selected correctly, I will see the latest content that is created on the "backup date selection".

I understand that for incremental backups, it needs all backups (from the first full backup and all incremental backups) to be working and available in order to restore the file.

A)Lets say MyBackup3.tib is corrupted or missing. If I restore the file newfilecreated4jan1pm.txt from "backup archive selection" MyBackup2.tib and "backup date selection" 5 Jan. Will newfilecreated4jan1pm.txt be resotred successfully?

B) Another question, if I have a file that is created on 2 Jan 9am. Now my MyBackup3.tib is corrupted or missing. Will a restore from "backup archive selection" MyBackup5.tib and "backup date selection" 5 Jan be successful to restore this file that is created on 2 Jan 9am

Hi dataman Hi dataman

You can’t be guaranteed it will be able to read the file as you are actually restoring form “MyBackup5.tib” which relies on all previous backups.

As you’ve said you only created your text file on Jan 4, you should be able to recover the file as it will actually restore that file from MyBackup4.tib as that’s when it was first backed up.

If you are performing file level backups this should be more so the case, but if you are performing image backups (which are allot better for most) the issue you might run into is it backups up HDD blocks and not entire files so on the file creation you might be able to restore but as you start editing that file different parts/versions of that file could be scattered around multiple incremental files meaning you can’t be sure you will be able to get the file back if you are missing one of the incremental files in the chain.

Having a corrupted TIB file is not something I’ve personally seen for many years now and if you have good reliable storage along with a backup process to take those files offsite as well you should not run into any issues. Most of our customers keep a copy of their backup files onsite as well as another copy of the files on another location or take them offsite so they always have at least 2 copies at a minimum of their systems.

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Just done some testing for you with the following setup with both file and image based backups:
- First backup (Full) – FirstBackup.txt file created
- Second backup (Inc) – SecondBackup.txt file created
- Third backup (Inc) – Thirdbackup.txt file created.

File backup
I was able to restore all file as expected from all levels, IF I manually removed the second backup archive (TIB file) I was still able to restore the Firstbackup.txt and Thirdbackup.txt files but obviously NOT the secondbackup.txt as the archive was missing!

Image Backup:
I was able to restore all file as expected from all levels, IF I manually removed the second backup archive (TIB file) I was still able to restore the Firstbackup.txt, SecondBackup.txt and Thirdbackup.txt files! The reason for this is I’m guessing the text files backed up were between 27 – 39 bytes in size (not even 1 KB in total). As image backups are done at a block level it’s very possible all 3x files were located in the same block that was backed up and is the reason why we are able to restore all 3 files even if one of the archives are missing (eg, all three text files were saved into the Thirdbackup.tib file as they fitted into a single ‘block’ of data) As mentioned above you can’t rely on this as it does more complex with changing files and larger files... you need to ensure you have all incremental backups but to answer your question it looks that ABR11 is able to restore files 100% even if there is a missing TIB file as long as all parts of that file are obviously not required from the missing archive!

Hope that helps...