Full Image vs Sector-By-Sector Backup

Discussion in 'Acronis True Image Product Line' started by Rube62, May 29, 2009.

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  1. Rube62

    Rube62 Registered Member

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    Currently on 15 day free trial of Acronis TI Home 2009....running WinXP with 150G internal HD of which currently I'm only using 15G, including operating system. Have a USB external 100G HD for backup purposes and this week I attempted to create a full disk image on this external drive. After clicking on "create an image of full disk or partition", I was give a choice of backing up sector-by-sector, which it said would require more space. Had a grand total of only 15G to back up, so thinking I had plenty of HD space on my 100G drive, I chose sector-by-sector backup. Went thru all the steps and the operation seemed to be working great....WRONG! The backup filled the entire 100G of my external drive, then quit....said I had run out of storage space. So I started the backup again, but didn't choose sector-by-sector backup. All went well and backup was completed, but the external backup shows to be only 8.3G in size. I had 15G to back up, but the backup on ext. HD shows to be only 8.3G in size. Are the non-sector-by-sector backups compressed?

    Also, would I have to have at least 150G backup space to be able to backup sector-by-sector? What is sector-by-sector backup and is there any advantage using it?

    Hope I've made my situation clear enough and thanks for any answers to my questions!
     
    Last edited: May 29, 2009
  2. seekforever

    seekforever Registered Member

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    The default compression for a TI image is Normal which usually gets the archive down to 65-70% of normally reported in-use space. TI does not include the pagefile or a hibernation file (if present) in the archive since they are always recreated on boot-up. A few byte placeholder is placed in the archive. There are about 3 levels of compression that can be selected but anything more than Normal takes a lot of time for little extra compression.

    The actual amount of compression you achieve depends on the type of files in the partition. Jpg, mpg, zip, rar, etc don't compress at all and some data files compress a large amount.

    A sector-by-sectore backup backs up every sector in the partition whether it is being used or not. So you would have needed a 150GB free space on the target drive to hold a 150GB sector backup.

    The sector-by-sector backup is useful if TI doesn't understand the file system which could occur if the HD is encrypted or corrupted. When TI makes an image it has to be able to make sense of the file structure on the disk. In earlier versions of TI, the sector-by-sector mode was not selectable but TI would revert to it automatically if it didn't understand the file structure.

    Another use of sector-by-sector is to make a backup of a corrupted HD that you wish to work on and still be able to get back the orignal screwed-up version in case you make it worse (you would be smarter to restore the backup to another HD and then work on it rather than the original).
     
  3. Rube62

    Rube62 Registered Member

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    Seekforever.....thanks for the info! Correct me if I'm wrong but you're saying that the 8.3G TI backup file on my external Hd is about normal for a backup of my 15G of internal HD C: info. Right?
     
  4. seekforever

    seekforever Registered Member

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    It is on the "well compressed" side of what I would expect but it probably is just fine. Did you have any file exclusions set in the options? IIRC, TI may have some file types like .tmp set automatically but I'm not sure; although it is unlikely this would make a big difference.

    You should test the TI rescue CD if you haven't already. Best way is to do a restore to a spare HD but next best method is to boot up the CD and do a Validate. Then run throught the restore wizard as if you were going to restore but cancel out on the final screen instead of telling TI to Proceed. Testing this CD is very important because it is Linux, not Windows, and may or may not have good drivers for your hardware. You don't want to find out it won't work when you really need it.
     
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