Acronis differential Backup
I use Acronis TIH 2011 on a Win7/64bit/prof. machine and just found out that the differential Backup method is not working as supossed.
I created on 26.02. a new diff. Backup job scheduler is off size of the Image 20 GB. 26.02. i let it run another time size of the Image 2,5 GB - looks good. I run it 27.02. Size: 20 GB?. I run it today it shows me again 20 GB - it is obviously doing full Backups.
Could someone explain me this and what to do that its diff. again. By the way. How do the following events influence a differential backup:
- Defragmenting a disk
- How is the index from Windows (for faster search) influencing diff/inc. Backups. What if i rebuild in Windows the index or change folders that will be included. Or if i change nothing but The service in the background indexes more files?
- What happens if i set the system back to a backup? I read somewhere in the internet that then always a new full backup will be made. is this true?
Hope for your help with this important questions. And Everything of this should be in the documentations with red ink at the beginning of the chapter - gives one a very insecure feeling when acronis does things you wouldn't expect...
Greetings!
Frank,
If you use a disk and partition backup, all sector changes will be recorded by the backup:
- a defragmentation process will not change the information, but its location on sectors, and therefore will create a lot of "changes" for the backup,
- windows processes typically update information on the disk (system volume information, hibernation files, page files, indexes) and those update sectors as well,
- if you restore an image, again, lots of sectors will be created and you end up with essentially a new full backup,
- if you update user folders, this will update disk sectors as well.
Hi Pat,
sorry i totally forgot about this in the last days. I Understand that New User Profile of course changes some sectors on the harddrive. But a couple of hundred MB shouldn't do a lot for a differ. Backup of an 20 GB Harddrive - or? How would you estimate the Windows Search Index - in my imagination all this does is create a little table on the harddrive that lists all the files. So what would you think how much this would add to a 20 GB image? Maybe 100 MB - or do i see this wrong when i would say that this is totally minor?
Thanks for your answer.
Frank,
Are you looking at the size of the TIB files on the destination location? I hope yes. The size indication in the UI is useless.
Hard to say what changes enough sectors for 20GB. It can be a combination of things. On my system, even if I don't do anything special, I end up having 1GB per day of incremental changes.
What is the size of the data that is being backed up altogether when a full is running?
If you use the "explore and recover" button, you will see all the backups tracked by ATI at the bottom of the window. If you mouse over each date, ATI will tell you whether this is a full or a differential.
Hey Pat,
what i meant is: you have a Partition with the System. when i back it up it is usually 30 GB of tib file. You already helped me, because my solution is now that i became friends with incremental backups. To Backup 30GB everyday took me this morning 2 min (not to much changes from yesterday) and that's o.k. for me. I think i can live with the (hopefully) little higher risk than full Backups.
Greetings!
TotalDataLoss,
If you switch to incrementals, don't forget to do a new full after a few incrementals, and make sure that any chain is at least validated once in a while. As a rule of thumb, you don't want to have your last full backup be so old that using it to restore would be a non-starter.