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Why is backup image so huge?

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I recently installed my old copy of Acronis True Image 2017 on a Windows 10 server machine in my home.  I would like to backup the windows/boot/system drive periodically, but the first backup made in an incremental set is the same size as the drive itself.  That would make sense -- if the drive was full -- however, Windows (and Acronis) reports that only 60 GB out of the drive's 250 GB total is in use.

So I'm trying to figure out why the default incremental backup's first "full" backup needs to include an [apparently] uncompressed image of every physical byte on the drive, whether the bytes are in use or not?

I'm expecting the first full backup to be roughly 60 GB in size, and subsequent incremental backups to be tiny, since all of the data that changes on my server is located on drives other than the system drive.  Only things that Windows updates on its own should be changing.

Can someone explain why the default settings for incremental (and image) backups appear to both create a full backup that overflows my 250 GB target drive for the backups when the source drive is using only 60 GB (out of 250)?  Also, can anyone help me figure out what the settings are to change the backup to a "sane" mode of operation?

Thanks!

0 Users found this helpful

Steven, welcome to these public User Forums.

The most likely cause of the backup being the same size as the source drive is that Acronis is using 'Sector-by-Sector' mode for the backup.

This can happen for various reasons.

The user can select this mode in the Advanced options for the task.

The drive is using a non-supported file system.

The drive has file system errors such as bad sectors etc.