restore option: MBR or Partition

Discussion in 'Acronis True Image Product Line' started by gede, Nov 25, 2006.

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  1. gede

    gede Registered Member

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    hello,
    I was wondering what the difference is between the options.
    When I went through the process of restore a partition at some point I got the option to restore the Partition or MBR.
    I'm not sure what MBR is and what would change if select this option.

    Can someone shed some light for me on this issue ?
     
  2. dld

    dld Registered Member

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    Here is an easy to understand description of the boot sequence:

    When a PC is turned on, it checks in with the BIOS. This is where the basic information about the computer exists, i.e. hard drive configuration data, time and date, plus many more weird and wonderful computer anatomical facts.
    When it discovers the hard disk (sometimes called the hard drive) and continues the boot sequence, it sends the heads of the hard drive, which are like a bunch of magnetic boxes mounted on arms kind of like the one on a record player, to the hard disk's platters. Think of platters as a bunch of plates on a spindle.
    A head reads the outside cylinder (called cylinder zero) on the platter. This cylinder is a donut ring of data, like a song on a record, though without the grooves that spiral inward. In the cylinder, it finds sector one (strangely there is no sector zero), which is a small area that contains data.
    The head reads the data there, which is where the Master Boot Record (or MBR) is always kept.
    The MBR tells the computer which partition to boot from. A partition is a distinct area of the disk that is assigned as drive "C". If the computer has a drive D, and perhaps drives E and F, then the hard drive is divided up into partitions. If it only has one partition, then the CD-ROM drive is assigned the drive letter D.
    The MBR is made up of computer code and data. It tells the computer about the partitions and tells it which partition is the "active" partition. Then the hard drive heads go to the active partition and looks for the Boot Record (or BR). The BR reports how many File Allocation Tables (FAT) there are (always two) and how big they are.
    The FAT is kind of a map that keeps track of all the files on a hard disk and their locations.
    The computer then reads the first FAT, skips over the second FAT and reads the root directory. This is where two hidden system files and a key file called "command.com" are kept. These take over the boot process. If the computer has Microsoft Windows on it then computer reads those next and the Windows is started.
    (Andy Walker in Cyberwalker.com)

    You only need to restore the MBR if you feel it is corrupt, i.e. if your HD will not boot.

    Here is a more involved description of the boot sequence.
     
    Last edited: Nov 25, 2006
  3. Long View

    Long View Registered Member

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    Normally you would only need to restore the partition. You would only need to restore the MBR if the MBR on your drive had been corrupted in some way or was incorrect.
     
  4. thomasjk

    thomasjk Registered Member

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    If you want a BOOTABLE disk when you restore select DISK which will automatically select MBR (Master Boot record ). If you only want to restore the partition to the existing disk select that option. Selecting DISK will overwrite everything on your existing disk and put it back to the way it was when the backup image was created. Selecting the partition will only restore the partiton to your current disk.
     

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  5. gede

    gede Registered Member

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    Thanks for the quick replies... I understand it now.
     
  6. foghorne

    foghorne Registered Member

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    Assuming you only have one partition, or don't care if your other partitions get overwritten.

    F.
     
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