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Re: [Xen-users] Guest O/S Questions

Marcus Brown wrote:

You're right.  fdisk (and AFAIK, modern partitioning tools) prefer to
start partitions on the first cylinder boundary.  The assumption here is
that each cylinder contains 63 sectors.

OK, but why skip this cylinder?
If you are creating an image with multiple partitions won't you need to
keep the partition table intact?
Ok, let's back track a little. The dd command I suggested is only useful for extracting the first partition from a partitioned disk image assuming that the first partition occupies all of the remaining disk space and starts on the 63rd sector.

It just so happens that if you partition a disk with only a single partition, with most partitioning tools, they'll always put the first partition on the 63rd sector.

I think the reason it chooses that sector is that it is the first sector on the second cylinder and it reserves the rest of the first cylinder for other uses (such as extra space for a boot loader).

If you're just exporting the whole disk, you don't need to do this command. You would only use this command if you were trying to export a file system image as a partition (as hda1, hda3, etc.).


Anthony Liguori


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