Differential backup size?

Using TI9 I took a full system backup = 7.1Gb
Next day took an incremental backup = 1.4Gb
After that I took a differential backup = 7.1Gb
Something must be wrong isn't it

 

Forgot to mention that right after taking the differential I took another full system image = 7.1Gb (about 50kb larger than the differential) Sure seems that the "differential" is really taking a full system backup

 

Hello pdegen,

Thank you for choosing Acronis Disk Backup Software.

Please make sure that you use the latest build (2337) of Acronis True Image 9.0 which is available at: http://www.acronis.com/homecomputing/support/updates/

To get access to updates you should create an account at:
http://www.acronis.com/homecomputing/my/
then log in and use your serial number to register your software.

Please uninstall any previously installed build by following Start -> Settings -> Control Panel -> Add or Remove Programs -> Acronis True Image, prior to installing build 2337.

If the problem still persists with the latest build, please clarify whether you have performed any actions with your hard drive before differential image creation?

Please create Acronis Report and Windows System Information as it is described in Acronis Help Post.

Please create an account, then log in and submit a request for technical support. Attach all the collected files and information to your request along with the step-by-step description of the actions taken before the problem appears and the link to this thread. We will investigate the problem and try to provide you with the solution.

Thank you.
--
Tatyana Tsyngaeva

 

My situation is almost exactly the same as that of pdegen - even to file sizes and sequences. I do have build 2337, but I suppose the suggested remedy is the same: uninstall and reinstall (I still have the installation file for 2337). Seems odd that our situations are so similar...daveferris

 

Hello daveferris,

Thank you for choosing Acronis Disk Backup Software.

Please be aware that the differential backup procedure compares the sector-by-sector structure of the data/partition/hard drive that you have backed up in the full image with the sector-by-sector structure of the data/partition/hard drive just before the differential backing up. That is why in cases you have defragmented your hard drive/partition the structure will be different from its state after the full image creation and the differential backup will take all the sector-by-sector changes. That is why the size of such a backup can be the same or even larger than the size of the full image.

Please clarify if you have not performed any layout changes (such as defragmentation) of your hard drive after the full image creation. If you have not then please create Acronis Report as it is described in Acronis Help Post and submit a request for technical support. Attach the collected report file to your request along with the step-by-step description of the actions taken before the problem appears and the link to this thread. We will investigate the problem and try to provide you with the solution.

Thank you.
--
Kirill Omelchenko

 

I reran some imaging with the following results (2337)
Full backup of drive C = 6.937Gb
Incremental of C = 0.156Gb
Differential of C = 0.163Gb
Diff AFTER defrag C = 3.691Gb

With storage space always at a premium, anyone who follows a scheduled regimen of defragmentation would be foolish to use the differential method. I think it ludicrous that the software engineers would design such a process.

 

I have defragmented the imaged drive since later differential backups so True Image is probably functioning normally. I will run another differential shortly (with no intervening defragmentation) and see if its length is reasonable. If so, won`t it be ok for me to delete all previous differentials after the full backup? Thanks..Dave

 

Hello daveferris,

Thank you for choosing Acronis Disk Backup Software.

Yes, you can delete all previous differential images to restore the last differential one.

Please find the difference between an incremental and differential image in FAQ article and in Acronis Solutions article.

You can also find more information on how to use Acronis True Image 9.0 in the respective User's Guide.

If you have any further questions please feel free to ask.

Thank you.
--
Tatyana Tsyngaeva

 

Many thanks for reassuring me how to proceed. I understand the differences between differential and incremental but I lacked confidence about which differential backups I could safely delete. Dave Ferris

 

You may be hard pressed to find a majority who agree that it's even necessary.

 

Conditions and needs do vary but I am in the "defrag rarely, if ever" camp. Everytime I do it I see no noticeable improvement in performance. Note that the disk analysis can show less than ideal numbers but it doesn't translate into obviously poor performance as seen by the user particularly on modern hardware.

The people who probably have most need for defragging are those running servers where a lot of files are added/deleted and desktop users whose drive is over 80% full.

If it makes you feel warm and fuzzy then by all means defrag.