Swapping the number of 2 partitions

[jd1008]

On 10/16/2014 10:25 PM, Cameron Simpson wrote:
> On 16Oct2014 18:45, jd1008 <jd1008 at gmail.com> wrote:
>> On 10/16/2014 03:32 PM, Cameron Simpson wrote:
>>> On 16Oct2014 12:55, jd1008 <jd1008 at gmail.com> wrote:
>>>> I am trying to avert having to dd out 2 partitions to external drive
>>>> and repartition and dd them back in.
>>>>
>>>> What I am trying to do is renumber partition 1 as partition 2
>>>> and partition 2 as partition 1.
>>>>
>>>> Is this possible? parted and fdisk and sfdisk do not seem to provide
>>>> such operations.
>>>
>>> sfdisk has a dump option. I would think you could dump the partition 
>>> table and reorder the partition records and reload it. I can't see 
>>> any reason that would not work.
>>
>> OK, it's just that I did not want to wreck the drive, as I was not sure
>> it would accomplish what I wanted.
>> So, P2 will be renamed P1
>> and P1 will be renamed (renumbered) P2.
>
> I would expect so. Note that I haven't done this myself.
>
>> Will this affect the other partitions P3 and P4 in any way?
>
> Shouldn't.
>
>> Such as, will it affect their starting offsets? Will the system
>> no longer be able to identify them by their existing UUID?
>
> AFAIK, the partition table is just a data structure laying out the 
> on-disk location of partition. The partition number is the record 
> number in the data structure. The physical location should be 
> independent. So you should be able to rearrange the records.
>
> I gather the UUID is embedded in the partition itself. But I have 
> never found out. But on that basis, the system should be just fine. In 
> fact, that's really the point of putting UUIDs on partitions - so the 
> OS config files don't have to track partitions locations and hard 
> drive locations.
>
> Note that this suggestions doesn't move any of the on-disk data around 
> (except the partition table itself I guess).
>
> Could you explain _why_ you want to renumber the partitions? Does 
> something have a hardwired desire to use "partition 1" or something?
>
> Cheers,
> Cameron Simpson <cs at zip.com.au>
>
> Sometimes when you fill a vacuum, it still sucks.
>         - attributed to Dennis Ritchie, about X
I think I need to do it because the windows partition for some reason
will not boot as partition 2 even though the boot.ini was edited to look
in partition 2  instead of partition 2.

So, I restored boot.init to look into partition 1, and then I will try 
to boot windows
from the grub2 menu (which I have also edited to look into msdos1 
instead of msdos2.

Not sure it will work, but worth a try.
I might save me a reinstall.