Windows 7: Incremental Backups Are Too Large?
I’m using True Image 2009.
With Windows XP, everything worked perfectly. I upgraded to 64-bit Windows 7. Now there’s a same problem.
One day one, I’ll run a full backup of C:\users\username. This includes all of my data, libraries, and user profile settings. That backup file is about 100Gb. Over the next 24 hours, I make no changes to anything. No new files, no downloads, no new program settings, nothing. On day 2, I run an incremental backup of C:\users\username. With XP this incremental finished in only a few seconds. This is what you expect because nothing changed since the last backup. With Windows 7, however, the incremental backup takes 40 minutes and the file is 30-40 Gb. What’s going on?
It appears that Windows 7 is making unchanged files appear to Acronis as changed files thereby causing them to be included in an incremental backup.
I know that there are some fairly easy work arounds, but I want to understand what’s actually going on here. Why does Windows 7 make old files look like new files?
There are many ways to check if a file has changed, either by sectors occupied, modified date or crc etc. You would think Acronis would be able to work alongside modern operating systems. Can someone from Acronis please state what technique your product uses to determine if a file has changed?
Hello all!
Thank you for bringing this up and let me answer your questions!
Unfortunately it is difficult to say why exactly the incremental was so big due to the lack of diagnostic information, and I would like to thank bboyer for his comment - defragmentation is one of the most common reasons for that.
I would like to ask you to check this KB article to verify whether you have any of the specified settings applied - they may be the cause of the large size of the incremental. Also please check whether there were any updates automatically downloaded and installed.
I would appreciate if you could keep us posted regarding the case so that we could provide you with the further assistance!
Darryl, thank you for your question! I will be glad to shed some light on that.
Every time the product makes a backup, it creates a snapshot. The snapshot is divided to several parts, to each of them has specific hash value. After the backup is made, the product deletes the snapshot, but saves the CheckSum. Then, when the incremental backup is being created, the snapshot is taken again. And after that the product verifies hash values of full and incremental images - and backs up sectors which have differences in CheckSum (hash value).
Let me know in case something seems confusing or you have any further concerns - I will be glad to help!
Thank you!
Incremental backup is broken in Windows. I am seeing the exact same behavior in Windows Vista Ultimate. In my case as a test, I ran the incremental immediately after the validation of the full. I know when defrag runs - it's right before the weekly full but in less than 10% of the cases does Incremental yield a substantially less number of files to backup throughout the week. To further confirm, I tested this same scenario under Windows XP SP3 and verified the same behavior.
This has been a pretty consistent message from the user community. Something other than defrag in both XP, Vista and 7 is causing this to happen. My build is 11345. It might also be noted that in Vista I am backing up data from a Bitlocked drive with the diffuser tuned on.
This seems to be a fairly simple thing to be able to verify. I have never NOT seen it happen. Quite a few other people are in the same boat apparently.
I am happy to provide diagnostic information to aid in getting this resolved but simply won't accept the defrag argument. This error is drastically reducing the amount of history I can keep in my backup system and may someday lead to data loss if a problem is not discovered right away.
thanks for posting this....I was wondering the same thing...I have diskeeper running continously and it is driving me made having to use system resources to back up one days work ie nominal changes and end up with an image of 175 gb as in incremental backup
Here it is February 9, 2015 (Acronis Backup 11.5 build 11.5.38929), Windows 7, and this same problem, dating back to 2009, persists. In my case, at least, it has nothing to do with disk defragmentation. I have had a service tag going on since December 1, 2014, and backup is still unsatisfactory. After a full backup of 1.77 TB, with very little change in disk content, incremental backup files are all huge: 665-811 GB, filling up my main 6TB backup drive in six days. Can this be fixed? If there is no way to resolve this problem, the only alternative is to uninstall Acronis and go back to Windows backup (bad, but better than this).