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On Tuesday 20 December 2005 03:45 pm, reader@×××××××.com wrote: |
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> How can I get a real eyes on look at what is in the MBR. I'm trying |
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> this: |
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> |
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> dd if=/dev/hda of=mbr.img bs=512 count=1 |
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> |
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> I thought maybe it could be mounted so: |
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> mkdir mbr |
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> mount -o loop mbr.img mbr |
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> |
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> But mount wants to know what `type' filesystem it is. I tried a few |
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> things but really didn't expect them to work like: |
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> ext2 msdos minix iso9660 |
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> |
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> None worked of course. So can this be done? Any one know what |
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> should be in there exactly and how to view it? |
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> |
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|
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The MBR isn't a partition itself, it merely stores the partition information. |
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As I understand it (and if somebody else has better info, or I've got things |
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backward, please correct me), the MBR is the first 512 bytes of the disk. |
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The first 446 bytes of it is the bootstrap loader code itself - the actual |
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workhorse that starts the system up to load the OS. The rest of it (66 |
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bytes) is the core partition information for the disk. Overwriting this part |
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of it will wipe out your partition table - not something you want to do. |
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|
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The book "Linux Desktop Hacks" has a section just on saving, fixing and |
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restoring the MBR. Rather than using bs=512, you'll want to use bs=446 when |
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overwriting the MBR (if you had a backup, and want to do it by hand), or use |
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a tool like grub-install (the Gentoo Handbook has a chapter on configuring |
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the bootloaders - LILO or GRUB - part 1, chapter 10). |
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|
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Good luck. |
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|
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-- |
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Eric Bliss |
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systems design and integration, |
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CreativeCow.Net |
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-- |
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gentoo-user@g.o mailing list |
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