Re: cloning a disk

On 8/8/26 05:07, mick.crane wrote:
> root@melon:~# fdisk -l
> Disk /dev/sdb: 111.79 GiB, 120034123776 bytes, 234441648 sectors
> Disk model: CT120BX500SSD1
> Units: sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disklabel type: gpt
> Disk identifier: D97B2271-48BB-4988-BEFA-5153C05D7C94
> 
> Device         Start       End   Sectors   Size Type
> /dev/sdb1       2048   2000895   1998848   976M EFI System
> /dev/sdb2    2000896 222339071 220338176 105.1G Linux filesystem
> /dev/sdb3  222339072 234440703  12101632   5.8G Linux swap


STFW "CT120BX500SSD1", I find the Crucial BX500 SSD:

https://www.crucial.com/support/ssd-support/bx500-support


Note that the production description/ marketing size is "120 GB" due to 
the International System of Units (SI, French: Système international 
d'unités):

https://en.wikipedia.org/wiki/International_System_of_Units

120034123776 bytes =~ 120 GB


> GPT PMBR size mismatch (234441647 != 468862127) will be corrected by write.
> The backup GPT table is corrupt, but the primary appears OK, so that 
> will be used.
> The backup GPT table is not on the end of the device.
> 
> 
> Disk /dev/sdg: 223.57 GiB, 240057409536 bytes, 468862128 sectors
> Disk model:  SA400S37240G
> Units: sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disklabel type: gpt
> Disk identifier: D97B2271-48BB-4988-BEFA-5153C05D7C94
> 
> Device         Start       End   Sectors   Size Type
> /dev/sdg1       2048   2000895   1998848   976M EFI System
> /dev/sdg2    2000896 222339071 220338176 105.1G Linux filesystem
> /dev/sdg3  222339072 234440703  12101632   5.8G Linux swap


STFW "SA400S37240G", I find the Kinston A400 SATA SSD in size "240 GB":

https://www.kingston.com/en/ssd/a400-solid-state-drive


Regarding cloning and the GUID Partition Table issues, WikiPedia appears 
to have good information:

https://en.wikipedia.org/wiki/GUID_Partition_Table


Cloning the 120 GB SSD to the 240 GB SSD is expected to cause GPT 
problems on the 240 GB SSD because the disks have different sizes:

*  The primary GPT header will have the wrong "Backup LBA" field value 
(Offset 0x20).

*  The primary GPT header will have the wrong "Last usable LBA" field 
value (Offset 0x30).

*  The secondary GPT header is in the wrong location.

*  I expect the secondary GPT header and/or table will have multiple 
wrong field values.


I suppose an expert could hack the GPT primary and secondary (backup) 
headers and tables with a hex editor (including "CRC-32" field values, 
Offset 0x10), but I would prefer using a tool:

1.  Clonezilla is well-known FOSS cloning software.  I believe it can 
deal with GPT disks of differing sizes:

https://clonezilla.org/

2.  gdisk(8) might be able to do the GPT adjustments after cloning with 
dd(1).

3.  sgdisk(8) is another possibility.


The KISS solution would be to do a fresh install of your preferred OS 
onto the 240 GB SSD, mount the 120 GB SSD read-only, and migrate your 
configuration settings and data from the 120 GB SSD to the 240 GB SSD.


David