Been running urbackup for a while but have noticed the incremental image size is large. On some computers it is about 25gb. Any ideas what might be doing this.
Maybe Is Because The PC Have 16+ GB Of Ram That Is Saved As SWAP/Hibernation File And That File Always Change?
4gb ram only. I thought that swap and hib files but would only be 8gb ish
Interesting…
Can You Compare The Contents?
Maybe Open Both The Images With VHDAttach ( https://www.jmedved.com/vhdattach/ )
No because I am using compressed image which makes a VHDZ file. If I uncompress this with the tool provided it creates a VHD from the full and latest incremental. As this is a live environment I can’t change to normal vhd as they backup everyday to a usb drive to take offsite.
In my experience this is the shadow storage area which is unfortunately marked as used during image backup time.
You can see the size of the shadowstorage using
vssadmin list shadowstorage /On=C:
If you are using a server version of Windows you can move the shadow storage to another volume using vssadmin resize shadowstorage. Also perhaps this registry key is set: Registry Keys and Values for Backup and Restore - Win32 apps | Microsoft Learn . And finally there could be other shadow copies which can be listed (and) deleted with vssadmin.
Have tried that uroni. Not much difference. Have tried a test machine with uncompressed vhd. When I open them as suggested by enone with vhdattach it shows all the files and says it is a differential backup instead of incremental. Is there an option to change this somewhere?
Just wondering if you ever found the root cause or workaround for this.
My incremental image backups are quite large too. For example, over 5gb of data was transferred when i only editted a text file in windows os.
No nothing. As it is a client it isn’t so bad. However, they are asking for a remote backup service now and this backup just creates too much data to transfer over the internet on a daily basis so will need to look for something else.
I believe that the incremental image backups are really just differential backups based off the last full backup.
If this is really the case, each incremental backup will be bigger than the previous one. Hopefully someone can confirm on this.
Is anybody able to confirm on this? Here is what I have tried on a Windows 2003 machine:
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Performed full image backup…total size about 5gb and took around hour
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Performed incremental image backup…backup was about 2.5gb in size and took about 45minutes
Is this normal? It seems that incremental backups are taking too long and big to backup
In this post, uroni says that image backup are differential:
It is quite old, I don’t know if something changed in the meanwhile.
Yes image backups behave indeed like differential and not incremental. But the thing is that the size of the differential backup is almost half every time. Even when I took a differential image backup 5 minutes after a full image backup completes successfully.
I just made a couple of tests using as client an XP virtual machine (server running on physical Debian 8).
A full compressed image of the system partition is 1,86 GB and took 13 minutes to complete. A subsequent differential image, started when the full had just ended, is 104 MB and took 6 minutes.
This seems quite coherent with your observations, considering i did absolutely nothing between the two backups (this is a clean machine, no services running on it).
I added a new virtual disk to the machine, put some files on it and tried again on this drive only; this was to be sure that absolutely nothing changed between backups.
The results are interesting: the full backup was 8,89 GB (18 minutes, I switched from WLAN to Gigabit), but two subsequent differentials came out as 384KB and 785KB, and both completed in 8 minutes.
From this, I suspect the system is making a lot of little changes to its files even when idling, causing Urbackup to assemble many of the 256 KB chunks in each differential image, even if just a few bytes have changed.
This is interesting. I noticed that the sizes of the differential backups conducted in your tests were much smaller as compared to mine.
In my tests on a Windows 2003 machine, a full backup takes about 1.9GB of compressed space while a differential takes up almost 1GB of compressed space!
I am not sure if it is due to the fact that Windows 2003 is a piece of server operating system and hence making more changes to the disk even when system is idle.
I compared the two images of the system disk with WinMerge.
The files differing between the two are about 70 MB, so I think this could explain the size of the differential image.
Could you analyze your images to see if the results are similar?
My results are somewhat similar to your observations.
It seems that the presence of a pagefile in the volume that I am backing up is causing big sized differential images backups for me.
I moved the pagefile to another volume and tried backing up again. This time, the differential image becomes significantly smaller than the full image backup.
Full image backup compressed size is now about 1.2GB with differential running about 32MB.
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Thanks for the testing!
The code to exlude the content of files is already present. I was relucant to enable it, though. The page file content will be excluded with the next major version, which will have a setting to switch between incremental/differential as well.
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Thanks for the update!
Any idea when the next major release will be rolled out?
Any update about differential/incremental backup? I just tried an incremental backup but with the last release it still create big incremental vhd. Even when I make 2 or 3 incremental image after few seconds…