[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: replacing boot and only disk drive

On Sun, 23 Nov 2014 12:14:25 +0100, Pascal Hambourg wrote:

> Pascal Hambourg a écrit :
>> Hendrik Boom a écrit :
>>> Unless the MBR or something related to it contains information about
>>> the size of the entire disk, which will now be wrong.
>> 2) If Windows boots from UEFI, I suppose that the original disk
>> partition table is in the GPT format. This format stores two copies of
>> the GPT header, one at the beginning (primary header) and one at the
>> end of the disk (secondary header). Each header has a pointer to the
>> other, so in a way the primary header has a reference to the end of the
>> disk where the secondary header is located. So, if you use dd to copy
>> the whole disk, the secondary header will not be at the end of the new
>> disk.
>> Maybe tools such as gdisk can fix this.
> Looking more carefully, there is more than just the address of the
> secondary GPT header. The GPT header contains also the last usable
> address for partitions which is near the end of the disk, just before
> the secondary partition table. Also, the protective MBR contains a GPT
> partition of the size of the disk - up to 2 TiB due to limitations of
> the MBR partition table format.
> See <http://en.wikipedia.org/wiki/GUID_Partition_Table>
> However, parted will detect that the disk is bigger than the partition
> table reports and ask to fix it. gdisk allows to fix it too.

The laptop now uses MBR partitions.  Since the new drive is only 2T, I 
don't expect to need GPT.  Thanks for the details, though I won't need to 
worry about these until my *next* hard disk enlargement.  And ... will 
Windows XP know what to do with GPT?  But maybe by then I will have 
successfully left Windows, even for the very last commercial applications.

-- hendrik

Reply to: