Do all hard drives have a master boot record?

wisdev · 08-31-2009, 03:21 PM

Because trying to Google that is apparently impossible.

I know -what- it is (first 512b, supposedly 'outside' of the partition, contains partition table). But what I don't know is that if I partition a hard drive starting at the first cylinder with fdisk -- will that overwrite the MBR?

lurko · 08-31-2009, 05:02 PM

Quote:

Originally Posted by wisdev

if I partition a hard drive starting at the first cylinder with fdisk -- will that overwrite the MBR?

It will not.

knudfl · 09-01-2009, 11:50 AM

This will

http://www.linuxquestions.org/questi...query.-606489/

jiml8 · 09-01-2009, 12:00 PM

Actually, if you use fdisk to partition the drive, it will overwrite the partition table that is already there. The partition table is 64 of the last 66 bytes of the MBR (the last two bytes are the signature block).

So, yes. fdisk DOES overwrite the MBR...that portion of it that it is concerned with.

Also, using dd to "zero" an MBR is dangerous; you can easily overwrite the partition table if you don't know what you are doing. The linked thread tells you quite adequately about that.

Crito · 09-02-2009, 06:42 AM

Partitioning doesn't blow away the MBR. But hard drives write whole sectors at a time. So even when you specify 446 with dd you're still, technically, rewriting all 512.